Abnormal Temporal Slowing on EEG Findings in Preclinical Alzheimer's Disease Patients With the ApoE4 Allele: A Pilot Study

INTRODUCTION

Currently, there are limited accessible and cost-effective biomarkers for preclinical Alzheimer's disease (AD) patients. However, the apolipoprotein E (ApoE) polymorphic alleles can predict if someone is at high (e4), neutral (e3), or low (e2) genetic risk for developing AD. This study analyzed electroencephalogram (EEG) reports from individuals with various ApoE genotypes, aiming to identify EEG changes and patterns that could potentially serve as predictive markers for preclinical AD progression.

METHODS

Participants aged 64-78 were selected from the patient database at an outpatient neurology clinic. Genotype studies were performed to determine ApoE status, followed by EEG analysis to identify any apparent trends. A case-control design was used, categorizing participants into cases (e2e3, e2e4, e3e4, e4e4) and controls (e3e3). EEG recordings were compared between the groups to identify potential differences in EEG characteristics, including abnormal temporal slowing, frequency, and ApoE genotype association.

RESULTS

Among 43 participants, 49% demonstrated evidence of abnormal temporal slowing on EEG. Of these, 48% displayed focal left temporal slowing, and 52% displayed bilateral temporal slowing. The right-sided temporal slowing was not observed. Among participants with abnormal slowing, 95% exhibited theta frequency (4-8 Hz) slowing, while only 4.8% displayed delta frequency (0-4 Hz) slowing. Among participants with the ApoE4 allele, 61.5% demonstrated evidence of abnormal slowing, compared to 43.3% without it. Furthermore, the presence of an ApoE4 allele was associated with a significantly higher proportion of males (54%) compared to those without it (13%) (p=0.009).

CONCLUSIONS

Although we did not find a statistically significant difference in temporal EEG slowing among different ApoE genotypes, our findings suggest a potential association between temporal slowing on EEG and the presence of an ApoE4 allele in individuals with preclinical AD. These observations highlight the need for further exploration into the potential influence of the ApoE4 allele on EEG findings and the utility of EEG as a complementary diagnostic tool for AD. Longitudinal studies with large sample sizes are needed to establish the precise relationship between EEG patterns, ApoE genotypes, and AD progression.

Investigation of Effects of Two Chronic Stress Protocols on Depression-Like Behaviors and Brain Mineral Levels in Female Rats: an Evaluation of 7-Day Immobilization Stress

We aimed to investigate the effects of two different chronic immobilization stress protocols on depression-related behaviors and brain mineral levels. Adult female Wistar albino rats were divided into 3 groups as follows (n = 10/group): control, immobilization stress-1 (45 min daily for 7 days), and immobilization stress-2 (45 min twice a day for 7 day). Stress-related behavior was evaluated by means of the forced swimming test (FST) and open field test (OFT). Minerals were analyzed using an inductively coupled plasma mass spectrometer. In the FST, swimming and immobility were significantly lower in the immobilization stress-1 and immobilization stress-2 groups. The climbing duration of the immobilization stress-2 group was higher than the control group. In the OFT, percentage of time spent in the central area was significantly lower in the immobilization stress-1 and immobilization stress-2 groups. Values of latency to center area, rearing, and grooming did not significantly differ between groups. In the immobilization stress-1 group, zinc was lower, and iron, copper, and manganese were higher than the control group. In the immobilization stress-2 group, copper and manganese were higher, and phosphate was lower than the control group. Our results showed that depression-related behaviors were more dominant in the immobilization stress-1 group. A decrease in the brain zinc level was valid only for the immobilization stress-1 group. These results point to the role of low brain zinc levels in the pathophysiology of depression.

Neurologist Attitudes on Practicing in Hawai'i

There is a shortage of neurologists nationwide, and the demand for neurologists is expected to increase in the upcoming years while the pool of practicing neurologists dwindles. Per Hawai'i Neurological Society, there were 44 practicing neurologists in the state of Hawai'i in 2019, representing a shortage of approximately 28 neurologists. Considering that Hawai'i is geographically, demographically, and culturally distinct compared to other states, a concern is that practicing neurology in Hawai'i poses unique challenges that may contribute to the low numbers of neurologists. An anonymous online survey was sent via email to all members of the Hawai'i Neurological Society from February 2019 to June 2019, inquiring about aspects of their practice they considered unique to Hawai'i. Twenty-three neurologists completed the survey, representing 52% of Hawai'i's neurology workforce. One neurologist completed a portion of the survey. Twenty-five percent of participants were born and raised or completed their medical education in Hawai'i. Self-reported reasons for practicing in Hawai'i included family, lifestyle, and patient population despite financial challenges and limited resources and opportunities. Participants suggested introducing a mandatory neurology rotation for Hawai'i medical students and creating an instate neurology residency program to combat the growing neurologist shortfall in Hawai'i. This survey identified local strengths and challenges in the field of neurology, potential ways to improve the practice environment in Hawai'i, and neurologists' perspectives on ways to address the neurology shortage.

Effects of agomelatine on electrocorticogram activity on penicillin-induced seizure model of rats

Agomelatine is a new antidepressant drug acting as an antagonist of 5-hydroxytryptamine receptor 2C (5-HTR_2C) and agonist of melatonergic receptors 1 and 2 (MT₁ and MT₂). Because of this dual action, it is an atypical antidepressant. The aim of this study was to investigate chronic anticonvulsant effects of agomelatine on penicillin-induced epilepsy model. Adult male Sprague-Dawley rats divided into four groups and were administered with tap water (vehicle), and agomelatine doses of 10 mg/kg, 50 mg/kg and 100 mg/kg for 14 days via oral gavage. After the last doses were given, epileptic seizures were induced by intracortical penicillin (500 IU/2.5 μl) application in rats under urethane (1.25 g/kg intraperitoneal) anesthesia. Electrocorticogram (ECoG) recordings were obtained from the somatomotor cortex through 90 min, and spike frequencies and amplitudes were analyzed. The spike frequency analyses revealed that only 50 mg/kg agomelatine administration decreased the spike frequencies of hypersynchronous discharge of neurons caused by penicillin (p < 0.05). No significant differences in amplitudes between experimental groups were observed. In addition, mRNA expressions of vesicular glutamate transporter 1 (VGLUT1) and vesicular gamma-aminobutyric acid transporter (VGAT) in response to the agomelatine active dose, 50 mg/kg, showed no significant effect of agomelatine on the mRNA expression. Our results indicate that chronic treatment with agomelatine may have potential anticonvulsant effects. Agomelatine may be a promising drug for epilepsy patients having depression due to its antiepileptic and antidepressant effects.

Cilostazol enhances atorvastatin-induced vasodilation of female rat aorta during aging

Statins have cholesterol-independent effects including an increased vascular nitric oxide activity and are commonly used by patients with cardiovascular disease. Such patients frequently have cardiovascular diseases, which may be treated with cilostazol, a platelet aggregation inhibitor. This study was designed to investigate whether combined use of cilostazol would increase the inhibitory effect of statin on vascular smooth muscle and how maturation would affect these responses. Female Wistar rats, aged 3–4 months (young) and 14–15 months (adult), were sacrificed by cervical dislocation and the thoracic aorta was dissected and cut into 3- to 4-mm-long rings. The rings were mounted under a resting tension of 1 g in a 20-ml organ bath filled with Krebs–Henseleit solution. Rings were precontracted with phenylephrine (10−6 M), and the presence of endothelium was confirmed with acetylcholine (10−6 M). Then, the concentration–response curves were obtained for atorvastatin alone (10−10 to 3 × 10−4 M; control) and in the presence of cilostazol (10−6 M) in young and adult rat aortas. This experimental protocol was also carried out in aorta rings, which had been pretreated with NG-nitro-l-arginine methyl ester (l-NAME, 10−4 M). Atorvastatin induced concentration-dependent relaxations in young and adult rat thoracic aorta rings precontracted with phenylephrine. The pIC50 value of atorvastatin was significantly decreased in adult rat aortas. In addition, pretreatment of aortas with cilostazol enhanced the potency of atorvastatin in both young and adult aortas. Incubation with l-NAME did not completely eliminate the relaxations to atorvastatin in the presence of cilostazol. These results suggest that combined application of cilostazol with atorvastatin was significantly more potent than atorvastatin alone. Combined drug therapy may be efficacious in delaying the occurrence of cardiovascular events.

Antinociceptive efficacy of levetiracetam in a mice model for painful diabetic neuropathy

BACKGROUND AND OBJECTIVE

Despite important advances in available knowledge, management of neuropathic pain remains incomplete, and results from experimental and clinical studies indicate that some anticonvulsants show promise for treating neuropathic pain. The aim of this study was to assess the antinociceptive efficacy of levetiracetam (LEV, ucb L059) in a mice model for painful diabetic neuropathy using the in vivo nociceptive behavioral 'hot-plate test.'

METHODS

The hot-plate test consisted of placing individual mice (adult male Balb/C) on the hot plate at 50+/-0.1 degrees C and timing the delay for the first hind paw lift (nociceptive threshold). After obtaining control values, diabetes was induced by injection of streptozotocin [200 mg/kg intraperitoneally (i.p.)] and 2 weeks after induction of diabetes (serum glucose > or =400 mg/dL) LEV was administered i.p. and hot-plate tests were repeated. Pain threshold values were determined and analyzed by Kruskal-Wallis one-way analysis of variance (ANOVA) followed by a pairwise comparison using a Dunnett's t-test on the ranked data.

RESULTS

LEV (60, 300 and 900 mg/kg) had no significant effect on the nociceptive threshold in normal mice (n=8 for each dose, P>0.05). There were significant decreases in pain threshold latency in diabetic mice compared with the normal healthy group and these were significantly and dose-dependently restored by much lower doses of LEV (20, 100 and 200 mg/kg) in a reversible manner.

CONCLUSION

Results obtained from the in vivo behavioral test lend support to the validation of the promising therapeutic potential of the novel antiepileptic agent LEV in the treatment of neuropathic pain.

Differential regulation of preovulatory luteinizing hormone and follicle-stimulating hormone release by opioids in the proestrous rat

We have investigated the role of mu- and kappa-opioid receptors in the central control of preovulatory LH and FSH release in the proestrous rat. Animals were anesthetized with chloral hydrate at 14:00 h on proestrus day. Following femoral artery cannulation, they were mounted in a stereotaxic apparatus. Morphine and U-50488H (benzene-acetamide methane sulphonate) were infused intracerebroventricularly either alone or in combination with naloxone and MR1452, respectively. Controls received sterile saline alone. Blood samples were obtained at hourly intervals between 15:00 h and 17:00 h. Plasma LH and FSH levels were measured by radioimmunoassay. Morphine did not significantly change plasma LH levels at 15:00 h and 16:00 h sampling intervals. A significant increase was observed at 17:00 h compared to the controls (p<0.05). U-50488H significantly increased LH levels at 16:00 h and 17:00 h (p<0.05). The co-administration of naloxone and MR1452 with mu- and kappa-agonist had no significant effect on LH levels at any sampling interval. In all groups, LH levels showed a linear rise over the sampling period between 15:00 h and 17:00 h. None of the treatments significantly altered plasma FSH levels which however, declined towards the end of the afternoon surge. In conclusion, we suggest that the secretion of LH and FSH is differentially regulated by mu- and kappa-opioid receptors. It is thought that in all groups chloral hydrate interfered with the LH surge secretory systems.

Effects of pinealectomy and exogenous melatonin on serum leptin levels in male rat

The effects of pinealectomy and exogenous melatonin (N-acetyl-5-methoxytryptamine) on serum leptin levels were investigated in rats. Exogenous administration of melatonin to intact rats resulted in significant decreases in serum leptin levels (P < 0.05) compared to those of the intact control group. Serum leptin levels were significantly elevated in the pinealectomised rats in comparison to the sham-pinealectomised animals (P < 0.001) and were significantly suppressed by exogenous administration of melatonin compared to those of non-treated pinealectomised rats (P < 0.001). Hormone concentrations in the melatonin-treated pinealectomised group were found to be similar to those seen in the sham-pinealectomised group. These results suggest that pineal gland has an effect on leptin release.

Melatonin inhibits spontaneous and oxytocin-induced contractions of rat myometrium in vitro

OBJECTIVE

The aim of this study was to investigate the effects of melatonin on spontaneous and oxytocin-induced contractility of pregnant and non-pregnant rat myometrium in vitro.

DESIGN

Myometrial strips were removed from virgin or late pregnant (21 days gestation) Wistar rats following decapitation and placed in an organ bath containing Krebs' solution at 37 degrees C and pH 7.4, constantly bubbled with 95% oxygen-5% carbon dioxide and isometric contractions were recorded. Effects of cumulative concentrations of melatonin (0.1 to 10 microM) on spontaneous and oxytocin-induced contractions were studied. Possible involvement of Ca(2+)-activated K (+) channels in inhibitory actions of melatonin was investigated by using apamin (100 nM).

RESULTS

Melatonin inhibited spontaneous and oxytocin-induced contractions of myometrium from both virgin and late pregnant rats in a dose-dependent manner. After inhibition of oxytocin-induced contractions by melatonin, application of prostaglandin F (2alpha) (1 microM) but not high KCl (30 mM) containing solution initiated contractile activity. Inhibitory response induced by melatonin (13 microM) was not affected by apamin (100 nM).

CONCLUSIONS

Data from this study demonstrates that melatonin inhibits spontaneous and oxytocin-induced contractions of myometrium from pregnant and non-pregnant rats. Although the exact mechanism is not clear, melatonin-induced inhibition of myometrial contractions may results from its interactions with Ca(2+) channels.

Effects of paint thinner exposure on serum LH, FSH and testosterone levels and hypothalamic catecholamine contents in the male rat

We have investigated the effects of thinner inhalation on serum LH, FSH and testosterone levels together with changes in hypothalamic catecholaminergic system in the male rat. A control group inhaled normal air ventilation. The remaining animals were divided into two groups and exposed to paint thinner in a glassy cage for 15 or 30 d. Toluene concentration (the largest constituent in thinner, 66%) was set at 3000 ppm in the inhalation air. At the end, all animals were decapitated and blood samples obtained. Serum LH and FSH levels were measured by RIA and testosterone by enzyme immunoassay. Following removal of brains on dry ice, medial preoptic area, suprachiasmatic nucleus, median eminence and arcuate nucleus were isolated by micropunch technique. Noradrenaline, 3,4-dihydroxyphenylglycol (DHPG) and dopamine concentrations of these hypothalamic areas were determined by HPLC-ECD. Fifteen-day thinner inhalation significantly suppressed serum LH and testosterone levels in parallel (p<0.001) compared to control group values (LH: 0.77+/-0.07; testosterone: 2.67+/-0.39). Thirty-day exposure markedly decreased LH levels (p<0.001), but surprisingly had no significant effect on testosterone. Serum FSH levels were not significantly altered in either group. Thinner inhalation for 15 or 30 d did not cause any significant change in noradrenaline, DHPG or dopamine concentrations in the hypothalamic regions examined (except in the arcuate nucleus). These results suggest that paint thinner has an anti-gonadotropic effect and may cause long-term endocrine disturbances in the male. It is thought that the hypothalamic catecholaminergic system is not involved in thinner inhibition of LH and testosterone secretion.

Influence of chronic morphine exposure on serum LH, FSH, testosterone levels, and body and testicular weights in the developing male rat

Opiate abuse has been a matter of serious concern in male adolescents. This study investigates the effects of chronic morphine administration on serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone levels, testicular histology, and body and testes weight in developing male rats. Animals were subcutaneously injected with morphine (5 mg/kg) or saline (1 mL/kg) twice daily for 30 days. Body weight determinations and injections were carried out under light ether anesthesia. At the end of the experiments, the rats were decapitated and blood samples were collected. Serum levels of LH and FSH were measured. Chronic morphine administration significantly decreased decreased serum testosterone (p < .02) and LH (p < .01) levels, but not FSH release compared to controls. Morphine exposure reduced body weight (p < .01), but had no significant effect on the testicular weight. When the testicular tissue was histologically examined, structural features of the seminiferous tubules and Leydig cells were similar in both saline and morphine-treated animals. The results suggest that opiates affect testosterone release through the hypothalamo-hypophyseal-gonadal axis rather than by a local testicular mechanism. Chronic morphine exposure during sexual maturation may have long-term endocrine disturbances in male rats.

Seasonal variation of prostatic acid phosphate and prostate-specific antigen in patients without prostatic malignancy

The seasonal pattern of prostatic acid phosphatase (PAP) and prostate specific antigen (PSA) in nonmalignant males was investigated. Serum levels were measured in 1,540 men during a 3-year period with radioimmunoassay methods using monoclonal antibody techniques. All of the tested individuals were free of prostatic malignancy. During each of the 3 years, PAP ans PSA showed a rise, especially in spring. The mean PSA level in spring showed a statistically important difference when compared with winter, fall and summer mean levels (p less than 0.05). However, no significant difference of PAP levels was estimated seasonally in the 3 years, which shows that an important marker of prostatic cancer can vary with seasons.