Association of digital measures and self-reported fatigue: a remote observational study in healthy participants and participants with chronic inflammatory rheumatic disease

Background

Fatigue is a subjective, complex and multi-faceted phenomenon, commonly experienced as tiredness. However, pathological fatigue is a major debilitating symptom associated with overwhelming feelings of physical and mental exhaustion. It is a well-recognized manifestation in chronic inflammatory rheumatic diseases, such as Sjögren's Syndrome and Systemic Lupus Erythematosus and an important predictor of patient's health-related quality of life (HRQoL). Patient reported outcome questions are the key instruments to assess fatigue. To date, there is no consensus about reliable quantitative assessments of fatigue.

Method

Observational data for a period of one month were collected from 296 participants in the United States. Data comprised continuous multimodal digital data from Fitbit, including heart rate, physical activity and sleep features, and app-based daily and weekly questions covering various HRQoL factors including pain, mood, general physical activity and fatigue. Descriptive statistics and hierarchical clustering of digital data were used to describe behavioural phenotypes. Gradient boosting classifiers were trained to classify participant-reported weekly fatigue and daily tiredness from multi-sensor and other participant-reported data, and extract a set of key predictive features.

Results

Cluster analysis of Fitbit parameters highlighted multiple digital phenotypes, including sleep-affected, fatigued and healthy phenotypes. Features from participant-reported data and Fitbit data both contributed as key predictive features of weekly physical and mental fatigue and daily tiredness. Participant answers to pain and depressed mood-related daily questions contributed the most as top features for predicting physical and mental fatigue, respectively. To classify daily tiredness, participant answers to questions on pain, mood and ability to perform daily activities contributed the most. Features related to daily resting heart rate and step counts and bouts were overall the most important Fitbit features for the classification models.

Conclusion

These results demonstrate that multimodal digital data can be used to quantitatively and more frequently augment pathological and non-pathological participant-reported fatigue.

POS0692 IANALUMAB (VAY736) SAFETY AND EFFICACY IN PATIENTS WITH SJOGREN’S SYNDROME: 52 WEEK RESULTS FROM A RANDOMISED, PLACEBO-CONTROLLED, PHASE 2B DOSE-RANGING TRIAL

Background:

Sjogren’s syndrome (SS) is an autoimmune disease affecting excretory glands and characterised by B-cell hyperactivity. Ianalumab (VAY736) is a human monoclonal antibody to B-cell activating factor receptor, engineered for direct ADCC-mediated B-cell depletion. A Phase 2b study evaluated the dose-response of VAY736 vs placebo (PBO) in EULAR SS Disease Activity Index (ESSDAI) change from baseline (CHB) and other secondary endpoints.

Objectives:

Primary results at Week (Wk) 24 were reported previously1. Here we report 52 Wk safety and efficacy from extended blinded treatment period 2 (TP2).

Methods:

190 patients (pts) were randomised equally to receive s.c. doses of VAY736 (5, 50, 300 mg) or PBO every 4 Wks (q4w). Eligible pts fulfilled American European Consensus Group (AECG) criteria, were anti-Ro/SSA+, had ESSDAI ≥6 and EULAR SS Patient Reported Index (ESSPRI) ≥5. At Wk 24, after completion of the first blinded TP (TP1), PBO-treated pts were switched to VAY736 150 mg, and pts on 300 mg were re-randomised to continue 300 mg or PBO for 28 Wks in TP2. Pts were followed post-treatment for ≥20 Wks. Safety was assessed for all periods. Due to lack of PBO-control in TP2, descriptive efficacy analysis was performed for ESSDAI, ESSPRI, Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F), Physician’s (PhGA) and Patient’s Global Assessments (PaGA), SF-36, and SS symptom diary (SSSD).

Results:

Overall, there was no dose dependency of treatment emergent adverse events (TEAEs) except for injection site reactions, which were mostly mild to moderate in severity. Lymphopenia and neutropenia were mostly grade (G)1 and G2, no G4. Most common TEAEs were infections and infestations in exposure-adjusted analysis of incidence rates. Nasopharyngitis and upper respiratory tract infections were the most common TEAEs, with no dose response (Table 1). Tracheobronchitis and pneumonia, were mild to moderate severity, not associated with absolute neutrophil count G3, and none led to treatment withdrawal.

At Wk 52, efficacy was sustained for pts who continued 300 mg in TP2 (ESSDAI, ESSPRI, PaGA, PhGA CHB: –9.06, –1.91, –22.03, –35.80, respectively). Efficacy was partially lost for pts switched to PBO at Wk 24 (Figure 1). Improvement was noted for PBO pts switched to 150 mg. Stimulated whole salivary flow at Wk 24 was improved for 300 mg (PBO-adjusted CHB 0.20 ml/min; P=0·037); last measurement at Wk 48 was 0.45 and 0.22 ml/min CHB in pts who continued 300 mg or PBO in TP2, respectively.

Conclusion:

Ianalumab 300 mg was well tolerated up to 52 Wks. Exploratory efficacy showed that continuous dosing of 300 mg s.c. q4w provided sustained clinical benefit. PaGA was the outcome that showed the most prominent change following switch to PBO or VAY736.

References:

[1]Dörner T, et al. [OP0302]. Ann Rheum Dis. 2020; 79 (suppl 1).

Table 1.

Key Safety Data (All Study Periods up to Week 52)*

n (%)[EAIR]15 mg24 Wks(N=47)50 mg24 Wks(N=47)150 mg28 Wks(N=47)Any 300 mg (N=47)Any AE43 (91.5)43 (91.5)44 (93.6)45 (95.7)[517.5][423.3][621.0][544.6]Any SAE3 (6.4)5 (10.6)8 (17.0)8 (17.0)[5.9][10.7][19.9][13.6]Infections and infestations (SOC)233 (70.2)31 (66.0)34 (72.3)38 (80.9)[154.1][119.2][162.0][127.7]Nasopharyngitis37 [15.5]4 [8.5] 9 [22.1]9 [16.5]Upper respiratory tract infections36 [12.8]8 [17.8]5 [11.6]8 [13.6]Bronchitis33 [6.2]3 [6.2]4 [9.5]4 [6.6]Tracheobronchitis31 [2.0]0 [0.0]0 [0.0]3 [5.0]Pneumonia31 [2.0]0 [0.0]1 [2.2]2 [3.3]Blood & Lymphatic Disorders (SOC)28 (17.0)9 (19.1)6 (12.8)9 (19.1)[18.0][20.8][14.3][16.8]Lymphopenia34 [8.4]4 [8.6]3 [6.8]2 [3.3]Neutropenia35 [10.7]1 [2.1]2 [4.5]4 [6.9]Injection site reaction34 (8.5)9 (19.1)17 (36.2)27 (57.4)

*Includes all safety data from TP1, TP2 and post-treatment follow-up; cut-off 06-Feb-2020

1EAIR, incidence rate per 100 subject years. For patient with an event, exposure time is censored at time of first event;

2Number of pts with at least one AE in SOC;

3PT, preferred term;

SOC, system organ class

Disclosure of Interests:

Thomas Dörner Consultant of: Novartis, GSK, Sanofi, Janssen, Eli Lilly, Grant/research support from: Deutsche Forschungsgemeinschaft, Simon J. Bowman Consultant of: Astrazeneca, Biogen, BMS, Celgene, Medimmune, MTPharma, Novartis, Ono, UCB, xtlbio, Robert Fox Consultant of: Novartis, Pfizer and Lilly, Xavier Mariette Consultant of: BMS, Galapagos, Gilead, Medimmune, GSK, Grant/research support from: Servier, Athena Papas Consultant of: Novartis, Grant/research support from: Novartis, Thomas Grader-Beck Consultant of: Novartis, Lilly, Grant/research support from: Abbvie, Celgene, Ben A Fisher Consultant of: Novartis, Roche, BMS and Servier, Filipe Barcelos Consultant of: Pfizer and Lilly, Salvatore De Vita Consultant of: Roche, Human Genome Science, Glaxo Smith Kline and Novartis, Hendrik Schulze-Koops Consultant of: Novartis, Robert J Moots Consultant of: Amgen, Chugai, Gilead, Lilly, Novartis, Pfizer, Roche, Grant/research support from: Amgen, Chugai, Gilead, Lilly, Novartis, Pfizer, Roche, Guido Junge Shareholder of: Novartis, Employee of: Novartis, Janice Woznicki Shareholder of: Novartis, Employee of: Novartis, Monika Sopala Shareholder of: Novartis, Employee of: Novartis, Wen-Lin Luo Shareholder of: Novartis, Employee of: Novartis, Wolfgang Hueber Shareholder of: Novartis, Employee of: Novartis

OP0302 IANALUMAB (VAY736), A DUAL MODE OF ACTION BIOLOGIC COMBINING BAFF RECEPTOR INHIBITION WITH B CELL DEPLETION, REACHES PRIMARY ENDPOINT FOR TREATMENT OF PRIMARY SJOGREN’S SYNDROME

Background:

Primary Sjogren’s syndrome (pSS) is a multi-organ autoimmune disease mainly affecting excretory glands and characterised by B-cell hyperactivity. No approved systemic treatment is available. Ianalumab (VAY736) is an anti-B-cell activating factor (BAFF) receptor fully human monoclonal antibody, engineered for direct ADCC-mediated B-cell depletion.

Objectives:

This phase 2b study aimed at establishing a dose-response relationship over a range of VAY736 doses, using change from baseline (BL) in EULAR Sjogren’s Syndrome Disease Activity index (ESSDAI) over 24 Weeks (Wks) as primary endpoint. The study is ongoing with a second blinded treatment period up to Wk52. Here we report efficacy and safety Wk24.

Methods:

190 patients (pts) were randomised 1:1:1:1 to receive monthly s.c. doses of VAY736 (5, 50, 300mg) or placebo (PBO). Prior to 1st-dose of study treatment, pts received methylprednisolone i.v. 250mg. Eligible pts fulfilled American European Consensus Group (AECG) criteria, were anti-Ro/SSA+, had ESSDAI ≥6 and EULAR Sjogren’s Syndrome Patient Reported Index (ESSPRI) ≥5. Statistical methods included MCP-Mod to assess dose-response on change of ESSDAI from BL and responder rate analysis to calculate the proportion of pts with ≥3 points improvement on ESSDAI. Secondary endpoints included ESSPRI, Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F), Physician’s (PhGA) and Patient’s Global Assessments (PaGA), SF-36, stimulated salivary flow (sSF), Schirmer’s test.

Results:

Primary endpoint was met with statistically significant dose-response for ESSDAI (Figure). The largest ESSDAI reduction was 1.92 points over PBO for VAY736 300mg at Wk24. Responder rate analysis on ESSDAI revealed for 300mg vs PBO responder rates of 42/47 (89.4%) vs 30/49 (61.2%), a difference of 28.1% (p=0.0019). No differences were seen for 5mg and 50mg vs PBO. PhGA change from BL was significantly different between 300mg and PBO (p=0.022). A numerical trend for sSF improvement for VAY736 300mg compared to PBO was notable at Wk24 (p=0.092). For secondary endpoints ESSPRI and FACIT-F, VAY736 treatment showed no benefits over PBO. PBO responses were generally high. Incidence of treatment emergent AEs was comparable across all studied groups, whereby site injection reactions were most frequent, mostly mild and showed a dose-response.

Conclusion:

Primary endpoint assessing ESSDAI was met, showing statistically significant dose-response for ianalumab with clinically important improvement for 300mg vs PBO. Preliminary safety profile of ianalumab was good.

Figure.

ESSDAI Change from Baseline over Time up to Week 24 Reveals a Statistically Significant Dose Response Relationship

Disclosure of Interests:

Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen, Simon J. Bowman Consultant of: Astrazeneca, Biogen, BMS, Celgene, Medimmune, MTPharma, Novartis, Ono, UCB, xtlbio, Glapagos, Speakers bureau: Novartis, Robert Fox Consultant of: Novartis, Pfizer and Lilly, Xavier Mariette Consultant of: BMS, Gilead, Medimmune, Novartis, Pfizer, Servier, UCB, Athena Papas Grant/research support from: Novartis, Consultant of: Novartis, Thomas Grader-Beck Grant/research support from: Abbvie, Celgene, Consultant of: Novartis, Lilly, Ben A Fisher Consultant of: Novartis, Roche, BMS and Servier, Filipe Barcelos Consultant of: Pfizer and Lilly, Salvatore De Vita Consultant of: Roche, Human Genome Science, Glaxo Smith Kline and Novartis, Hendrik Schulze-Koops Grant/research support from: Pfizer Inc, Robert J Moots: None declared, Guido Junge Shareholder of: Novartis, Employee of: Novartis, Janice Woznicki Shareholder of: Novartis, Employee of: Novartis, Monika Sopala Shareholder of: Novartis, Employee of: Novartis, Wen-Lin Luo Shareholder of: Novartis, Employee of: Novartis, Wolfgang Hueber Shareholder of: Novartis, Employee of: Novartis

Phase Ib Study of Panobinostat and Bortezomib in Relapsed or Relapsed and Refractory Multiple Myeloma

Purpose

Despite advancements, prognosis for patients with relapsed/refractory multiple myeloma (MM) is poor, and novel therapies are needed. Panobinostat is a potent deacetylase inhibitor that elicits synergistic effects on MM cells in combination with bortezomib. This phase Ib study sought to determine the maximum-tolerated dose (MTD) of panobinostat plus bortezomib in patients with relapsed or relapsed and refractory MM.

Patients and Methods

In the dose-escalation phase (n = 47), panobinostat was administered orally thrice weekly every week in combination with bortezomib (21-day cycles). After MTD determination, patients were evaluated in an expansion phase (n = 15) that incorporated a 1-week treatment holiday of panobinostat, with dexamethasone added in cycle 2. Additional assessments included safety, pharmacokinetics, and efficacy per International Myeloma Working Group criteria.

Results

The MTD was established at panobinostat 20 mg plus bortezomib 1.3 mg/m2. Grade 3 or 4 adverse events (AEs) included thrombocytopenia (85.1%), neutropenia (63.8%), and asthenia (29.8%) in the escalation phase, and thrombocytopenia (66.7%), neutropenia (46.7%), and fatigue (20.0%) in the expansion phase. At MTD in the escalation phase, eight patients (47.1%) discontinued therapy as a result of AEs, whereas five patients (33.3%) discontinued treatment in the expansion phase. Expansion phase patients demonstrated greater median treatment duration. Overall response rate (ORR) was 73.3% in the expansion phase and 52.9% at the escalation phase MTD. Among bortezomib-refractory patients, the ORR was 26.3%, and 42.1% of patients had ≥ minimal response.

Conclusion

The MTD of panobinostat plus bortezomib was determined and demonstrated activity in patients with relapsed or relapsed/refractory MM, including bortezomib-refractory patients. A phase II/III clinical trial program (Panobinostat or Placebo With Bortezomib and Dexamethasone in Patients With Relapsed Multiple Myeloma [PANORAMA]) has been initiated.

Ex vivo skin absorption of terpenes from Vicks VapoRub ointment

BACKGROUND

The pharmaceutical market offers a wide range of inhalant drug products applied on the skin that contain essential oils and/or their isolated compounds, i.e. terpenes. Because there are few data concerning the skin penetration of terpenes, especially from complex carriers, the goal of this study was to determine the ex vivo skin absorption kinetics of chosen terpenes, namely eucalyptol, menthol, camphor, alpha-pinene, and beta-pinene, from the product Vicks VapoRub.

MATERIAL/METHODS

Human cadaver skin was placed in a flow-through diffusion chamber and the product was applied for 15, 30, and 60 min. After the application time the skin was separated into layers using a tape-stripping technique: three fractions of stratum corneum and epidermis with dermis, and terpenes amounts in the samples were determined by gas-chromatography.

RESULTS

The investigated terpenes showed different absorption characteristics related to their physicochemical properties and did not permeate through the skin into the acceptor fluid. Eucalyptol had the largest total accumulation in the stratum corneum and in the epidermis with dermis, while alpha-pinene penetrated into the skin in the smallest amount.

CONCLUSIONS

The short time in which saturation of the stratum corneum with the terpenes occurred and the high accumulation of most of the investigated terpenes in the skin layers proved that these compounds easily penetrate and permeate the stratum corneum and that in vivo they may easily penetrate into the blood circulation.

Patupilone in chemotherapy-pretreated patients with advanced colorectal cancer (CRC) receiving nutritional support and intensive diarrhea management: A phase I multicenter trial

3593

Background: In previous clinical studies, a positive effect was noted in patients with CRC heavily pretreated with chemotherapy who received the novel microtubule stabilizer patupilone (EPO906; epothilone B) once-weekly or q3wk; however, susceptibility to diarrhea was high and response rates were modest. This dose-escalation trial examined the safety/efficacy of 3 patupilone regimens in chemotherapy-pretreated patients with CRC who received nutritional support and intensive diarrhea management. Methods: Patients with histologically confirmed CRC, without ileo- or colostomy or history of abdominal/pelvic irradiation, and who relapsed or were refractory after ≤4 prior chemotherapy regimens received nutritional support, intensive diarrhea management if needed, and patupilone as IV bolus q3wk or 1-or 5-day continuous IV (CIV) q3wk at doses of 6–10 mg/m2. Additional inclusion criteria: ≥1 measurable lesion; age ≥18 years; WHO performance status <2; no hepatic, renal, or hematologic impairment. Nutritional supplementation: ω-3 fatty acids, pre- and probiotics, antisecretory factor, and glutamine. Diarrhea management: appropriate clinical care, loperamide, opium tincture, codeine, and octreotide. Dose escalation was per protocol following a 3+3 design. The primary objective of this trial was to determine the maximum tolerated dose of the 3 patupilone treatment schedules in these patients. Results: Forty-four patients were enrolled: bolus, n = 22; 5-day CIV, n = 3; 1-day CIV, n = 19. Mean age 58.8 years; 95% Caucasian; 54% men. In the 5-day CIV arm, enrollment was closed at the 6.5-mg/m2 dose level since 2 dose-limiting toxicities (severe diarrhea) were reported. With bolus and 1-day CIV, the current doses are 10 and 9 mg/m2, respectively. The most common adverse events in the 43 patients evaluable for safety were diarrhea (70%), asthenia (23%), and nausea (21%). Grade 3 diarrhea occurred in 9 patients (21%). Overall response: 4 partial responses and 13 stable disease. Conclusions: Preliminary results suggest that patupilone monotherapy administered q3wk + intensive diarrhea management may prove beneficial in patients with CRC who progressed after 2–3 chemotherapy regimens.

[Table: see text]

Neuroprotective effects of NS-7, voltage-gated Na+/Ca2+ channel blocker in a rodent model of transient focal ischaemia

The aim of the present study was to characterize neuroprotective activity of NS- 7, a mixed voltage-gated sodium and calcium channel blocker in a model of transient focal ischaemia in rats. Ischaemia was induced by a 75 min reversible occlusion of middle cerebral artery (MCAo) using a nylon filament. NS-7 (0.5 mg/kg i.v.) or 0.9% NaCl (1 ml/kg i.v.) were infused over 3 min. starting 30 min after the MCAo. Infarct analysis was performed 72 h after ischaemia. Application of NS- 7 produced significant protection seen in neurological tests and diminished brain damage by 37% in total infarct (17.7+/- 3.0% vs. 27.9 +/- 3.2% control; [p < 0.01]; t-test), 47.8% in cortical infarct size by (8.5 +/- 2.4% vs. 16.2 +/- 2.4% control; [p < 0.01]), and by 21.5% in striatal infarction (9.2 +/- 0.8% vs. 11.7 +/- 0.9% control; [p < 0.05]). The results indicate that NS- 7 has potential for neuroprotection against transient ischaemic insult.

Neuroprotective activity of a nanoparticulate formulation of the glycineB site antagonist MRZ 2/576 in transient focal ischaemia in rats

The objective of the present study was to characterise the neuroprotective activity of the novel glycineB site NMDA (N-methyl-D-aspartate) receptor antagonist MRZ 2/576 (8-chloro-4-hydroxy-l-oxo- 1,2-dihydropyridazino[4,5-b]quinolin-5-oxide choline salt, CAS 202807-80-5) in a rodent model of focal cerebral ischaemia. Since the solubility of MRZ 2/576 at a physiological pH, is minimal and adequate concentrations can be achieved only at relatively high basic pH the in vivo use of the substance is substantially limited. Therefore, a special nanoparticle formulation was developed to provide means for lengthy i.v. administration of experimentally relevant doses within the physiological range of pH. Focal ischaemia of 75 min duration was induced in rats by a reversible occlusion of the middle cerebral artery (MCAo). MRZ 2/576 (18 mg/kg over 10 min followed by 18 mg/kg/h over 6 h) or placebo treatment was initiated immediately after onset of MCAo. Neurological deficit was evaluated daily for 3 consecutive days and then brain infarct analysis was performed. MRZ 2/576 significantly improved the neurological score at 24 h and 72 h post stroke (p < 0.05 vs. placebo). It also produced a 53.0% reduction of total infarct size, 60.4% of cortical and 42.3% of striatal infarction (p < 0.05 vs. placebo). Temporary drug-induced hypothermia and ataxia were observed during infusions. This leads to the conclusion that prolonged administration of the glycineB site antagonist MRZ 2/576 in form of the nanoparticle suspension ameliorates ischaemic damage induced by the transient MCAo in rats. The results suggest that nanoparticles hold promise as an effective strategy e.g. for substances with physico-chemical characteristics that otherwise would preclude them from pre-clinical development and/or clinical application.

Chronic cerebral hypoperfusion in the rat enhances age-related deficits in spatial memory

Ten-week old rats were subjected to chronic mild hypoperfusion by a permanent bilateral ligation of common carotid arteries (2VO). Animals were repeatedly tested in 8-arm radial maze at 1 week, 3, 10 and 16 months after the surgery to investigate long term effects of 2VO on spatial learning and memory. Occluded rats showed initially mild deficits in reference (RM) and working (WM) memory that were progressing with time and reached level of marked differences 16 months after the surgery. Advanced age significantly influenced cognitive function in both groups but the observed deterioration was more pronounced in 2VO animals. We suggest that the long-lasting reduction of cerebral blood flow combined with ageing can result in the enhanced cognitive impairment of aged individuals.

Middle cerebral artery occlusion produces secondary, remote impairment in hippocampal plasticity of rats - involvement of N-methyl-D-aspartate receptors?

There is increasing evidence that focal cerebral ischaemia produces remote functional alterations that may substantially contribute to the post-stroke neurological outcome. Changes initially limited to peri-infarct areas may evolve and spread via transneuronal connections to other structures. In the present study we investigated whether focal ischaemia produced by 2-h occlusion of the middle cerebral artery (MCAo) in SD rats may influence the physiological function of the hippocampus. Three days later in vitro long-term potentiation (LTP) was studied in hippocampal slices from ipsi- and contralateral hemispheres. In rats with MCAo LTP was not-inducible in the ipsilateral hippocampus, while the contralateral side expressed stable potentiation (6.6+/-4.1 vs. 35. 0+/-8.0%, respectively). Treatment with 6-h i.v. infusion of an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist MRZ 2/579 starting at reperfusion not only preserved but additionally enhanced ipsilateral LTP, while a slight insignificant decrease was observed in the contralateral side (77.0+/-18.4 vs. 20.8+/-6.5%). The study demonstrates post-stroke functional changes in the hippocampus that can be modulated by NMDA receptor antagonists.

Inhibitory effect of NPY on the picrotoxin-induced activity in the hippocampus: a behavioural and electrophysiological study

The effect of neuropeptide Y (NPY) on the picrotoxin-induced activity was studied in rat brain hippocampal slices in vitro and after intrahippocampal injection in vivo. In the hippocampal slices, NPY (0.1-0.5 microM) inhibited the picrotoxin-induced epileptiform activity recorded extracellularly in CA1 and CA3 hippocampal pyramidal cells. Similar inhibition was induced by the Y2 receptor agonist NPY13-36, which indicates that the effect of NPY was due to activation of Y2 receptors. In behavioural studies, rats with chronically implanted cannulae were injected unilaterally into the CA1 hippocampal region with a 1 ml volume of the studied substances. Picrotoxin in a dose of 1 mg (1.6 nmol) induced behavioural excitation, shakes and weak signs of epileptic behaviour. NPY in a dose of 2 mg (470 pmol), but not 1 mg, inhibited some excitatory effects of picrotoxin, but did not change the epileptic symptoms. The obtained results suggest that NPY has an inhibitory action in the hippocampus, which can be observed in vitro and also in a behavioural study.

Inhibitory effect of intrahippocampal NPY injection on amphetamine-induced behavioural activity

The aim of the present study was to investigate the influence of intrahippocampal neuropeptide Y (NPY) administration on the rats' behaviour. The CA1 field or dentate area (GD) of the dorsal hippocampus was chronically implanted with intracerebral cannulae. NPY (or redistilled water in the control group) was injected bilaterally or unilaterally in a volume of 1 microliter to each hippocampus, in a dose of 1 or 2 micrograms per rat. A separate group of rats was pretreated with amphetamine (1 mg/kg, s.c.), 15 min before a bilateral microinjection of NPY (2 micrograms) into the CA1 region. Immediately after the intrahippocampal injection, the rats' behaviour was tested in an open field box. It was found that NPY did not change the locomotor and the exploratory activity after either CA1 or GD administration to non-pretreated animals. In amphetamine pretreated rats, NPY injected into the CA1 field inhibited the amphetamine induced increase in sniffing and rearing and, to a lesser extent, the number of line-crossings. The obtained results may suggest an inhibitory action of NPY in the CA1 hippocampal field on the behavioural hyperactivity.