Congenital CNS primitive neuroectodermal tumor: case report and review of the literature

A 30-week gestational age male fetus was found to have a congenital neoplasm involving the posterior cranial fossa, identified by fetal ultrasound examination in utero. Histological and immunohistochemical examination confirmed a diagnosis of primitive neuroectodermal tumor (PNET) of the posterior fossa, also referred to as medulloblastoma. Although PNETs have been well documented, there are relatively few reports of these occurring as congenital neoplasms. We present a case of an in utero, congenital PNET with a review of the literature and discussion of the criteria defining congenital tumors.

Components of life model in practice

This paper attempts to cover the stages recognised as being part of the research process in order to investigate the problem related to the lack of individualised patient care documentation and supporting theoretical framework, which is both understood and accepted by the staff within Accident and Emergency (A & E). With the advent of the United Kingdom Central Council's (UKCC) document Standards of Record Keeping (1993), there is now greater need for a model to be implemented and accepted by those working in the department. The Components of Life model was introduced following a literature search, as this seemed to be a potential solution to the problem, since it emphasises the individual practising self-care activities in order to maintain independence. To initiate staff to the Components of Life model, a half study day was organised on the subject of models of care within A & E. Jones was invited to discuss his approach to A & E nursing care. Subsequently, a draft document relating to nursing care was created using the Components of Life model as a framework. The initial draft was followed with a printed document which was put into use for a trial period of 4 weeks, followed by a review. The review collected both positive and negative comments from the staff, the negative proved to be the most constructive as they served to make improvements within the care plan. Perhaps the most important success as a result of completing this project is that of increased staff enthusiasm and motivation--especially in wanting to make the documentation work.

Comparison of the responses of human melanocytes with different melanin contents to ultraviolet B irradiation

Melanin is thought to serve in photoprotection. To investigate this, we have compared the responses of cultured human melanocytes derived from different pigmentary phenotypes (skin types I-VI) to a single irradiation with different doses of UVB light, ranging between 11.7 and 70.1 mJ/cm2. After UVB irradiation, heavily pigmented melanocytes had the same percent survival but a greater capacity to resume proliferation than their lightly pigmented counterparts. A significant increase in melanin content was observed in heavily pigmented but not in lightly pigmented melanocytes. Irradiation with UVB light blocked melanocytes, regardless of their melanin content, in G1, and induced the expression of the tumor suppressor p53 protein within 4 h. This induction steadily increased up to 48 h in lightly pigmented melanocytes; however, in heavily pigmented melanocytes, p53 level peaked at 24 h after UVB treatment and declined thereafter. Additionally, DNA from lightly pigmented melanocytes contained significantly higher numbers of cyclobutane pyrimidine dimers than did DNA from heavily pigmented melanocytes after irradiation with increasing doses of UVB light. We speculate that the prolonged induction of p53 in lightly pigmented melanocytes arrests them in G1 for a long time period in order to repair extensive DNA damage. The above described differences might partially explain the increased susceptibility of individuals with lightly pigmented skin compared to individuals with dark skin to the photodamaging and photocarcinogenic effects of sun exposure.

Selective elimination of malignant stem cells using photosensitizers followed by light treatment

The pros and cons of purging of either bone marrow or peripheral blood stem cell preparations for autologous transplantation for cancer has been debated strongly over the past decade. Recent data implicating the role of minimal residual disease in autografted marrow in cancer relapse have renewed interest in this question. There is a considerable body of literature supporting the possibility that photosensitizer molecules in combination with light might provide a therapeutic window permitting selective elimination of malignant stem cells while sparing those of normal lineage. Molecules of this class are known to be taken up more actively by most malignant cells, and intracellular concentrations are critical in their cytotoxic effect when they are activated by light at an appropriate wavelength. The present paper reviews the observations made over the past decade on a variety of photosensitizers and their effects on hemopoietic progenitors.

Paraneoplastic retinopathy in association with large cell neuroendocrine bronchial carcinoma

Images

Baculovirus expression and affinity purification of protein E2 of classical swine fever virus strain Alfort/187

The genome region encoding the major envelope glycoprotein E2 (gp55) of the classical swine fever virus (CSFV) strain Alfort/187 was cloned and sequenced. The E2 gene, either with or without additional authentic 5'-terminal sequences coding for two variants of a putative signal sequence, was used to construct recombinant baculoviruses expressing the respective glycosylated and nonglycosylated E2 protein in insect cells. The signal sequences mediated glycosylation in insect cells, but no efficient secretion of the protein into the cell culture supernatant was observed. Six histidine residues introduced at the carboxy terminus of E2 allowed purification of E2 protein by Ni(2+)-chelate affinity chromatography. The proteins obtained were characterized and their immunological properties were compared by western blot analysis.

Development of a marrow transplant regimen for acute leukemia using targeted hematopoietic irradiation delivered by 131I-labeled anti-CD45 antibody, combined with cyclophosphamide and total body irradiation

In an attempt to decrease the relapse rate after bone marrow transplantation (BMT) for advanced acute leukemia, we initiated studies using 131I-labeled anti-CD45 antibody (BC8) to deliver radiation specifically to hematopoietic tissues, followed by a standard transplant preparative regimen. Biodistribution studies were performed in 23 patients using 0.5 mg/kg trace 131I-labeled BC8 antibody. The BC8 antibody was cleared rapidly from plasma with an initial disappearance half-time of 1.5 +/- 0.2 hours, presumably reflecting rapid antigen-specific binding. The mean radiation absorbed doses (cGy/mCi131I administered) were as follows: marrow, 7.1 +/- 0.8; spleen, 10.8 +/- 1.4; liver, 2.7 +/- 0.2; lungs, 2.1 +/- 0.1; kidneys, 0.7 +/- 0.1; and total body, 0.4 +/- 0.03. Patients with acute myelogenous leukemia (AML) in relapse had a higher marrow dose (11.4 cGy/mCi) than those in remission (5.2 cGy/mCi; P = .001) because of higher uptake and longer retention of radionuclide in marrow. Twenty patients were treated with a dose of 131I estimated to deliver 3.5 Gy (level 1) to 7 Gy (level 3) to liver, with marrow doses of 4 to 30 Gy and spleen doses of 7 to 60 Gy, followed by 120 mg/kg cyclophosphamide (CY) and 12 Gy total body irradiation (TBI). Nine of 13 patients with AML or refractory anemia with excess blasts (RAEB) and two of seven with acute lymphocytic leukemia (ALL) are alive disease-free at 8 to 41 months (median, 17 months) after BMT. Toxicity has not been measurably greater than that of CY/TBI alone, and the maximum tolerated dose has not been reached. This study demonstrates that with the use of 131I-BC8 substantially greater doses of radiation can be delivered to hematopoietic tissues as compared with liver, lung, or kidney, which may improve the efficacy of marrow transplantation.

Prostanoid synthesis in the spinal cord enhances excitability of dorsal horn convergent neurones during reperfusion of ischaemic receptive fields on the rat's tail

In 40 rats anaesthetized with enflurane, we identified convergent dorsal horn neurones responding to both noxious (pinch) and innocuous (brush) mechanical stimulation of their receptive fields on the tail. We recorded extracellular activity before and during ischaemia of the receptive fields, as well as during subsequent reperfusion. Two NSAIDs, indomethacin and diclofenac sodium, or saline were applied locally to the spinal cord before the induction of ischaemia. During ischaemia, spontaneous activity of the neurones increased significantly, and the responses to both pinch and brush were reduced significantly; indomethacin and diclofenac sodium had no effect on either spontaneous activity or sensitivity to mechanical stimuli. The neurones became hypersensitive to both pinch and brush during reperfusion of their receptive field, and receptive field size increased. Application of indomethacin and diclofenac sodium to the spinal cord abolished both the hypersensitivity and the increase in receptive field size. Our results indicate that spinal cord prostanoid synthesis facilitates the enhanced excitability of dorsal horn convergent neurones to both noxious and innocuous mechanical stimuli during reperfusion of their receptive fields, but does not affect the neurones' responses to receptive field ischaemia, nor their responses to mechanical stimuli in the absence of a conditioning stimulus.

The influence of ipsapirone, a 5-HT1A agonist, on sleep patterns of healthy subjects

Ipsapirone is a new pyrimidinylpiperazine ligand specific for 5-HT1A receptors, with potential therapeutic use in affective disorders. Because 5-HT is involved in the regulation of sleep, we investigated the effect of ipsapirone hydrochloride on sleep patterns in 18 normal, healthy subjects of both sexes. Compared to placebo, ipsapirone 5 mg administered by mouth three times daily for 14 days decreased rapid eye movement (REM) sleep duration and, by the tenth day of treatment, began to reduce slow wave sleep (SWS) duration. The decrease in REM sleep occurred in the first 3 h of sleep. The latency to REM sleep was increased from the first night following ipsapirone administration, remained increased throughout the 14 days of administration, and fell to equal latency on placebo immediately administration ended. Subjective assessments of sleep revealed no differences between ipsapirone and placebo. Our experiments confirm a role of 5-HT1A receptors in sleep. The effects of ipsapirone on the sleep patterns of patients with affective disorders still need to be determined.

T-cell-rich B-cell lymphoma. A clinicopathologic study of eight cases

Although T-cell-rich B-cell lymphoma (TCRBCL) is a recently recognized form of non-Hodgkin's lymphoma (NHL), limited information regarding its incidence, cellular origin, morphologic spectrum, and biologic behavior is currently available. In this study, the clinicopathologic features of eight patients with TCRBCL are presented. This neoplasm comprised about 1% of all NHLs seen at Emory University Hospital over 2 years. The male-to-female ratio was 1.6, and the mean age at diagnosis was 60 years. At presentation, TCRBCL was nodal in 88% of the patients and widely disseminated in 50% of the patients. A complete remission was seen in three of the five patients treated with combination chemotherapy that was directed at intermediate grade NHL. Three patients received inadequate or incomplete chemotherapy. One of these patients later achieved a complete remission with more intensive therapy. Two of the patients were not evaluable for response to therapy. The actuarial and disease-free survival rates of the group at 5 years were 72% and 21%, respectively. Morphologically, the lymph nodes in seven of eight cases were diffusely obliterated, whereas one had markedly expanded interfollicular zones that lead to an initial diagnosis of T-zone lymphoma. All tumors were characterized by no more than 25% large lymphoid cells, which were scattered in a background of small lymphocytes with round or irregular nuclei. The presence of numerous histiocytes imparted a lymphoepithelioid appearance in two cases. Although immunoperoxidase stains of frozen tissue were initially suggestive of a peripheral T-cell lymphoma in some cases, paraffin immunoperoxidase stains clearly established the B-cell nature of the large cells, whereas most of the small cells were T lymphocytes. The clonal nature of the large cells was confirmed in seven cases by monotypic immunoglobulin (Ig) light chain restriction or Ig gene rearrangements. Epstein-Barr virus genomic DNA was detected in two of the six cases tested by polymerase chain reaction or Southern blot analysis, but no evidence of a bcl-2 rearrangement was found in any of the five cases examined. These findings indicate that TCRBCL is an uncommon form of NHL with a therapeutic response and overall survival consistent with intermediate grade lymphoma. Paraffin immunoperoxidase stains and occasionally genotypic analysis are required to exclude the diagnosis of PTCL or diffuse lymphocyte predominant Hodgkin's disease. The authors found no morphologic or molecular evidence to support a follicular center cell origin in these cases of TCRBCL.

Serological cross-reaction between Legionella spp. and Capnocytophaga ochracea by using latex agglutination test

Cross-reactivity between Legionella spp. and Capnocytophaga ochracea was noted by latex agglutination tests (Serobact Legionella; Disposable Products, Adelaide, Australia). Four of 11 (36%) C. ochracea isolates agglutinated with latex reagents designed to identify Legionella pneumophila serogroups. C. ochracea isolated on buffered charcoal yeast extract media may give false-positive results in this Legionella latex agglutination assay.

Blood and brain temperatures of free-ranging black wildebeest in their natural environment

Using miniature data loggers, we measured the temperatures of carotid blood and brain in four wildebeest (Connochaetes gnou) every 2 min for 3 wk and every 5 min, in two of the animals, for a further 6 wk. The animals ranged freely in their natural habitat, in which there was no shelter. They were subject to intense radiant heat (maximum approximately 1,000 W/m2) during the day. Arterial blood temperature showed a circadian rhythm with low amplitude (< 1 degree C) and peaked in early evening. Brain temperature was usually within 0.2 degrees C of arterial blood temperature. Above a threshold between 38.8 and 39.2 degrees C, brain temperature tended to plateau so that the animals exhibited selective brain cooling. However, selective brain cooling sometimes was absent even when blood temperature was high and present when it was low. During helicopter chases, selective brain cooling was absent, even though brain temperature was near 42 degrees C. We believe that selective brain cooling is controlled by brain temperature but is modulated by sympathetic nervous system status. In particular, selective brain cooling may be abolished by high sympathetic activity even at high brain temperatures.

Diazepam attenuates hyperexcitability and mechanical hypersensitivity of dorsal horn convergent neurones during reperfusion of the rat's tail following ischaemia

We have investigated the involvement of the GABAA-benzodiazepine receptor complex in nociceptive activity of convergent neurones in the spinal cord during ischaemia and reperfusion of their receptive fields on the rat's tail. In enflurane anaesthetized rats, extracellular recordings were made from convergent neurones located throughout the dorsal horn before, during and after 30 min of ischaemia. Following intrathecal saline pretreatment, there was a significant increase in spontaneous firing rate during ischaemia (219 +/- 21%, P < 0.02, n = 10) which persisted during reperfusion. After 10 min of reperfusion, the neurones exhibited a greater response than before ischaemia to both innocuous brush (54 +/- 11%, P < 0.05, n = 10) and noxious pinch (72 +/- 14%, P < 0.02, n = 10) and the enhanced sensitivity persisted over the 60-min reperfusion period. During reperfusion, receptive field size increased in most neurones tested. Intrathecal diazepam (100 and 500 micrograms) abolished the hyperexcitability and the hypersensitivity to both innocuous and noxious mechanical stimulation during reperfusion. The highest dose of diazepam (500 micrograms) also attenuated the increase in spontaneous firing rate during ischaemia. Diazepam, at the doses tested, had no effect on receptive field enlargements during reperfusion. The effect of 100 micrograms of diazepam was partially reversed by flumazenil (1 mg/kg i.p.) but not by naloxone (1 mg/kg i.p.). In the absence of ischaemia, diazepam had no effect on spontaneous firing rate nor on the responses to innocuous or noxious mechanical stimulation. Our results support an antinociceptive role for benzodiazepines in the dorsal horn elements responsible for reperfusion hyperalgesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Distributional patterns of multiple sclerosis brain lesions. Magnetic resonance imaging--clinical correlation

Forty-one patients with multiple sclerosis were studied with magnetic resonance imaging (MRI) and a battery of neuropsychological tests to determine the pattern of lobar distribution of lesions in the relapsing-progressive and relapsing-remitting forms of the disease. Correlation of lesions with the patient's cognitive and emotional dysfunction was also obtained. The results of this study indicate that patients with relapsing-progressive multiple sclerosis are characterized by the large or coalescent lesions located predominantly in the periventricular area. These lesions were more frequently found in the parietooccipital areas and were accompanied by significant cognitive dysfunction and severe personality changes. The patients with relapsing-remitting disease, however, were characterized by punctiform or small discrete lesions predominantly located in the intermediate and subcortical areas. These lesions were more frequently seen in the parietooccipital regions and the patients had significantly less severe cognitive and emotional involvement than did the patients with relapsing-progressive disease. Recognition of these patterns was easily accomplished by MRI. In this investigation MRI studies were utilized as an index of the pathological changes occurring at one point in time in the evaluation of the disease. Only repeated MRI studies and continuous clinical observation can establish the final diagnosis.

Detection of chromosome 12q amplification in sarcomas by chromosome microdissection and interphase fish

We describe the microdissection of a homogeneously staining region (hsr) in the neuroblastoma cell line NGP-127 which contains the SAS gene. Fluorescence in situ hybridization (FISH) of this probe to NGP-127 cells confirms its derivation from the hsr, while FISH to normal chromosomes establishes that the hsr is composed of sequences from two segments of chromosome 12q. The hsr microdissection probe yields fluorescent signals which are sufficiently intense to readily identify amplification of homologous sequences in interphase nuclei.

Optimal therapy for stress gastritis

OBJECTIVE

The authors compared the results of sucralfate versus H2 blocker +/- antacid as prophylaxis for stress ulceration in an intensive care unit patient population.

SUMMARY BACKGROUND DATA

Stress ulceration carries high morbidity and mortality for the patient who is critically ill. Gastric acid neutralization is an effective prophylaxis. The impact of increased gastric colonization with bacterial pathogens on nosocomial pneumonia after acid neutralization is unclear. The efficacy of sucralfate prophylaxis for stress ulceration and its the effect on the nosocomial pneumonia rate is controversial. The financial implications of sucralfate prophylaxis versus H2 blocker-based acid neutralization therapy has not been studied.

METHODS

Ninety-eight injured patients who were critically ill and who required intubation and intensive care unit (ICU) support for at least 72 hours without gastric feeding were randomized and received either maximal H2 blocker infusion therapy (continuous infusion of ranitidine at 0.25 mg/kg/hr after a loading dose of 0.5 mg/kg) plus antacids (for persistent pH < 4) or sucralfate (1 g every 6 hours via nasogastric tube) for stress ulcer prophylaxis. Efficacy in preventing stress ulcer complications was determined. The impact of each therapeutic approach on development of nosocomial pneumonia was evaluated. The charges/cost for each approach was analyzed.

RESULTS

Heme-positive gastric aspirates occurred in 99% of the patients, whereas 12 (7 in the H2 blocker group and 5 in the sucralfate group) were grossly positive for blood. However, only one from each group required transfusion, and one in the H2 blocker group required operation. Gastric colonization preceded tracheobronchial colonization in five patients in the H2 blocker group and one patient in the sucralfate group; simultaneous gastric/oropharyngeal colonization preceded positive tracheobronchial growth in six patients who received H2 blocker and one patient who received sucralfate. The overall pneumonia rate was 27.5% in the H2 blocker group and 20.8% in the sucralfate group (p = 0.48). Days on ventilator were 13.5 versus 9.1, (p = 0.06), ICU lengths of stay were 14.7 versus 10.2 (p = 0.06), and hospital lengths of stay were 27.8 versus 20.0 (p = 0.029) for the H2 blocker group and sucralfate group, respectively. Based on current charges and protocols for optimal H2 blocker and sucralfate prophylaxis, use of sucralfate rather than H2 blockers would decrease the annual cost by more than $30,000 per bed.

CONCLUSIONS

Sucralfate is as efficacious as maximal H2 blocker therapy for stress ulceration prophylaxis, and may have a beneficial effect on the incidence of nosocomial pneumonia. Sucralfate has a major reduction on nursing requirements for stress ulcer prophylaxis and would save approximately $30,000 per ICU bed per year in patient charges.

Body temperatures of lambs and their mothers measured by radio-telemetry during parturition

Using temperature-sensitive radio-telemeters chronically implanted in the abdomens of 8 fetal lambs and their mothers, we measured body temperature changes induced by parturition. Maternal body temperature rose at 0.70 +/- 0.06 degrees C/hour (mean +/- SEM) in the final stages of labour. Fetal body temperature also rose, but at a significantly lower rate, 0.45 +/- 0.06 degrees C/hour (p < 0.05). The fetus appears to be protected from excessive hyperthermia during the birth process.

Repeated treatment with chimeric anti-CD4 antibody in multiple sclerosis

We treated 21 multiple sclerosis patients with two to four doses of cM-T412, a chimeric monoclonal antibody against the CD4 antigen found on helper/inducer T lymphocytes. The mean number (+/- standard error) of circulating CD4 lymphocytes decreased from 888 (+/- 81) cells/mm3 at baseline to 246 (+/- 18) after treatment. At 1 year after the last treatment, the CD4 count had recovered to only 335 (+/- 32). The antibody had no effect on CD8 lymphocytes, B lymphocytes, or other leukocytes. Side effects were minimal. Despite the prolonged depletion of CD4 lymphocytes, no opportunistic infections occurred. Only 1 patient had a possible allergic reaction. Most patients were clinically stable, but a few progressed. We conclude that repeated treatment with cM-T412 is effective in reducing the number of circulating CD4 lymphocytes and has no limiting side effects.

Prolonged endurance exercise and sleep disruption

To determine whether exercise duration effects the recovery sleep following exercise, eight fit male endurance athletes, ages 23-42 yr, had their sleep electrophysiologically studied. This was done on four separate occasions: after a day on which no specific exercise was performed; after a day of a 15-km run; after a 42.2-km run day; after a day in which the athletes participated in a strenuous ultra-triathlon. Sleep patterns following the no exercise day and the 15-km and the 42.2-km run days were similar. The sleep pattern of the ultra-triathlon day when compared with the other three days showed significantly increased wakefulness and delayed and decreased rapid eye movement (REM) sleep. The duration of slow wave sleep (SWS) in the first 6 h after lights out, however, was no different. The increased wakefulness and decreased REM clearly indicate increased stress after the ultra-triathlon. REM sleep appears to be a more sensitive index of exercise induced stress than SWS.

Typical and atypical NK1 tachykinin receptor characteristics in the rabbit isolated iris sphincter

1. A contraction of the rabbit isolated iris sphincter smooth muscle follows activation of either tachykinin NK1 or NK3 receptors. We have here characterized the pharmacological activity profiles of various tachykinin receptor agonists considered to have NK1-receptor-preferring activity in this preparation. 2. Two groups of NK1-receptor-preferring agonists could be distinguished in terms of a common pharmacological profile. The first group (Group 1) included [Glp6,L-Pro9]-SP(6-11) (septide), [Glp6]-SP (6-11), substance P methyl ester, delta-aminovaleryl-[L-Pro9, N-MeLeu10]-SP(7-11) (GR73632), and [Apa9-10]-SP. The second group (Group 2) included [Pro9]-SP, substance P, physalaemin and ranamargarin. 3. Under control conditions, the responses to Group 1 agonists were relatively fast in offset (time for reversal of maximal responses, 11.2-18.2 min), and were antagonized by NK1-receptor-selective antagonists (range of pKB estimates vs various agonists; GR82334, 7.1-8.2; (+/-)-CP-96,345, 8.9-9.5; RP67580, 7.0-7.4). Following incubation of the tissue with phenoxybenzamine (20 microM, 10 min), the affinity of GR82334, tested against the Group 1 agonists, substance P methyl ester and septide, was not significantly different (P < 0.05; n = 7-18) to that determined in untreated tissues (substance P methyl ester pKB 7.5 +/- 0.1 and 7.2 +/- 0.2, respectively; septide 7.7 +/- 0.2 and 7.9 +/- 0.2, respectively). Further, response offset times (5.0-8.5 min) were little reduced as compared to those observed in untreated tissues. 4. Under control conditions, the response to Group 2 agonists was markedly slow in offset (times for reversal of maximal responses, 51.4-70.4min), and was not attenuated significantly by the NK1-receptor-selective antagonists GR82334 (I MicroM), (+/-)-CP-96,345 (0.1 MicroM) or RP67580 (1 MicroM). In contrast,after phenoxybenzamine pretreatment, responses to Group 2 agonists reversed rapidly (times for reversal of maximal responses, 13.1-24.2 min), and were now antagonized by GR82334 (pKB estimates, 6.4-7.1).5. The responses to the NK3-receptor-selective agonist Succ-[Asp6,Me-Phe8]-SP(6-l1) (senktide) were relatively fast in offset (time for reversal of maximal response was 18.6 +/- 1.7 min) and were not inhibited by GR82334 (10 MicroM; n = 5). The contractile response resulting from co-application of the Group 1 agonist, septide together with senktide, did not exhibit prolonged response offset kinetics.6. Assuming simple competition at equilibrium, these data from the rabbit iris smooth muscle could be explained either by interaction of the various ligands with two separately-existing NK1 receptor-subtypes or -isoforms; or alternatively by a preferential interaction of the two agonist groups with different binding domains on a common NK1 receptor.

Emergence neophobia correlates with hippocampal and cortical glutamate receptor binding in rats

Previous work from our laboratory indicated that emergence neophobia is highly correlated with perforant path long-term potentiation (LTP) in rats. In the present study, we examined the relationship between hippocampal and cortical alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors and emergence behavior in rats. Emergence neophobia was assessed in an exploratory task that provided a choice between a novel alley and a familiar nest box. Quantitative autoradiography using radiolabeled ligands specific for the AMPA subclass of glutamate receptors was performed on frozen brain sections. Both [3H]AMPA and [3H]CNQX (6-cyano-7-nitro-[3H]quinoxaline- 2,3-dione, an AMPA receptor antagonist) binding in the dentate gyrus (stratum moleculare), hippocampal area CA1 (stratum radiatum), and the parietal cortex overlying the hippocampus were significantly correlated with emergence behavior. The correlations indicated that neophobic rats, which had longer latencies to enter the novel alley, made fewer entries into the alley, and spent less time in the novel alley during a 10-min test than their neophilic counterparts, had higher levels of AMPA receptor binding. These results suggest that individual differences in specific hippocampal AMPA receptors reflect variability in a specific class of hippocampal-dependent behaviors.