Memory Effects of Benzodiazepines: Memory Stages and Types Versus Binding-Site Subtypes

Benzodiazepines are well established as inhibitory modulators of memory processing. This effect is especially prominent when applied before the acquisition phase of a memory task. This minireview concentrates on the putative subtype selectivity of the acquisition-impairing action of benzodiazepines. Namely, recent genetic studies and standard behavioral tests employing subtype-selective ligands pointed to the predominant involvement of two subtypes of benzodiazepine binding sites in memory modulation. Explicit memory learning seems to be affected through the GABAA receptors containing the α1 and α1 subunits, whereas the effects on procedural memory can be mainly mediated by the α1 subunit. The pervading involvement of the α1 subunit in memory modulation is not at all unexpected because this subunit is the major subtype, present in 60% of all GABAA receptors. On the other hand, the role of α5 subunits, mainly expressed in the hippocampus, in modulating distinct forms of memory gives promise of selective pharmacological coping with certain memory deficit states

Effect of acute physostigmine and verapamil treatment on aggressive and depressive behavior in rats with lesioned nucleus basalis magnocellularis

In order to investigate the effects of physostigmine and verapamil on aggressive (test of foot shock induced aggression) and depressive (learned helplessness test) behavior, ten days after bilateral lesions of the nucleus basalis magnocellularis (NBM), adult male Wistar rats were acute treated (30 min before the test) with physostigmine (0.045, 0.060 and 0.075 mg/kg, s.c.) or verapamil (1.0, 2.5, 5.0 and 10.0 mg/kg, s.c.) Physostigmine in dose of 0.075 mg/kg and verapamil in doses 2.5 and 5.0 mg/kg significantly prolongated the escape latency period in the learned helplessness test and thus produced a consolidation of depressiveness in NBM-lesioned rats. Tn contrast to that, there was no restitution of aggressive behavior in NBM-lesioned rats treated with both drugs. It could be concluded that both physostigmine and verapamil exerts a significant influence on depressive, but not on aggressive reaction in an animal model of Alzheimer's disease

Humoral and cell-mediated immune responses following lesions of the nucleus basalis magnocellularis in the rat

The present study was undertaken to elucidate whether electrolytic lesions of nucleus basalis magnocellularis-NBM (an animal model of Alzheimer's disease-AD) may influence humoral and cellular immune responses in adult male Wistar rats. For this purpose intact control (IC), sham-operated (SO) and NBM-lesioned rats were divided into two main groups: (1) rats immunized with sheep red blood cells (SRBC) for plaque-forming cell (PFC) response and anti-SRBC agglutinins, and (2) rats immunized with bovine serum albumin in complete Freund's adjuvant (BSA-CFA) for anti-BSA antibody production, Arthus and delayed hypersensitivity skin reaction to BSA. PFC responses and anti-SRBC agglutinins as well as diameter and expression of edema/induration of Arthus/delayed skin reaction and titer of anti-BSA antibody were significantly lower in NBM lesioned rats (compared to IC and SO). The results showed that in NBM-lesioned rats both the humoral and cellular immune responses were suppressed