Age-related changes in medial septal cholinergic and GABAergic projection neurons and hippocampal neurotransmitter receptors: relationship with memory impairment.

The hippocampus, which provides cognitive functions, has been shown to become highly vulnerable during aging. One important modulator of the hippocampal neural network is the medial septum (MS). The present study attempts to determine how age-related mnemonic dysfunction is associated with neurochemical changes in the septohippocampal (SH) system, using behavioral and immunochemical experiments performed on young-adult, middle-aged and aged rats.

Modulation of spatial memory and expression of hippocampal neurotransmitter receptors by selective lesion of medial septal cholinergic and GABAergic neurons.

The medial septum (MS) is an important modulator of hippocampal function. The degree of damage in which the particular set of septo-hippocampal projections contributes to the deficits of spatial memory with concomitant changes of hippocampal receptors expression has not been studied till present. Therefore, we investigated spatial memory and the expression level of cholinergic (α7 nACh and M1), GABAergic (α1 subunit of GABAA) and glutamatergic (NR2B subunit of NMDA and GluR 1 subunit of AMPA) receptors in the hippocampus following selective lesions of cholinergic and GABAergic septo-hippocampal projection.

Memantine treatment prevents okadaic acid induced neurotoxicity at the systemic and molecular levels.

The present study was designed to investigate the effects of okadaic acid intracerebroventricular (ICV) injection on memory function and expression level of α7 subunit of nicotinic acetylcholine receptor (nAChR) and NR2B subunit of NMDA glutamate receptors in the hippocampus, as well as effect of the antidementic drug memantine on okadaic acid induced changes at systemic and molecular levels in rats. Okadaic acid was dissolved in artificial cerebrospinal fluid (aCSF) and injected ICV 200 ng/10 μl. Vehicle control received 10 μl of aCSF ICV bilaterally.

EFFECTS OF SELECTIVE CHOLINERGIC AND GABAERGIC LESIONS OF THE NUCLEUS BASALIS MAGNOCELLULARIS ON PLACE OR RESPONCE LEARNING IN PLUS-SHAPED MAZE.

In the present study we evaluated effects of selective cholinergic or GABAergic lesions of the nucleus basalis magnocellularis (NBM) using immunotxins 192 IgG-saporin and GAT1-SAP on place and response learning in plus-shaped maze. In current behavioral paradigm rats learned food-rewarded mazes that were efficiently learned using either place or turning strategies. A histological evaluation indicated that 192 IgG-saporin lesions specifically depleted cholinergic neurons but did not result in noticeable damage to the GABAergic cells within NBM.

MEMANTINE ATTENUATES THE OKADAIC ACID INDUCED SHORT-TERM SPATIAL MEMORY IMPAIRMENT AND HIPPOCAMPAL CELL LOSS IN RATS.

In the present study, the possible beneficial effect of memantine on the Okadaic Acid (OA) induced spatial short-term memory impairment was examined in spatial alternation task, and the neuroprotective potential of memantine on OA-induced structural changes in the hippocampus was evaluated by Nissl staining. OA was dissolved in artificial cerebrospinal fluid (aCSF) and injected intracerebroventriculary (ICV) 200 ng in a volume of 10 μl bilaterally. Vehicle control received aCSF ICV bilaterally.