Medial septal modulation of hippocampal single-unit activity was examined by assessing the behavioral and physiological consequences of reversibly inactivating the medial septum via microinjection of a local anesthetic (tetracaine) in freely behaving rats trained to solve a working memory problem on a radial maze. Reversible septal inactivation resulted in a dramatic, but temporary (15-20 min),...

..........................................................................................1 CHAPTER I: INTRODUCTION....................................................................3 CHAPTER II: Steroidal Regulation of synaptic density in the magnocellular division of the medial preoptic nucleus (MPN mag) of the Syrian Hamster..............................19 Introduction.........................

The medial septum (MS) complex modulates hippocampal function and related behaviors. Septohippocampal projections promote and control different forms of hippocampal synchronization. Specifically, GABAergic and cholinergic projections targeting the hippocampal formation from the MS provide bursting discharges to promote theta rhythm, or tonic activity to promote gamma oscillations. In turn, the ...

Fluorescence histochemical studies have demonstrated a topographical distribution of dopaminergic nerve terminals in limbic forebrain and cortical regions4, 9-11. These data, together with biochemical evidence indicating significant amounts of dopamine (DA) in these regionsl,XS, zl, suggest the existence of a major anatomical pathway projecting to forebrain areas which originate in mesencephali...

A series of experiments was carried out testing the hypothesis that the septal region decreases the hippocampal susceptibility to hyperexcitability states through theta rhythm generation. Medial septal neurons were simultaneously recorded with hippocampal field potentials to investigate the septo-hippocampal function in the pilocarpine model of chronic epilepsy. The theta rhythm from chronicall...

Sex differences were investigated in cholinergic neurons of the septal-diagonal band region of adult rats subjected to neonatal treatment with 3,3',5-triiodo-L-thyronine (T3). Neonatal hyperthyroidism resulted in a 44% increase in specific activity of choline acetyltransferase (ChAT; EC 2.3.1.6) in adult male rat septal-diagonal band region, whereas no change in ChAT activity could be detected ...

OBJECTIVE The septal nuclei are important limbic regions that are involved in emotional behavior and connect to various brain regions such as the habenular complex. Both the septal nuclei and the habenular complex are involved in the pathology of schizophrenia and affective disorders. METHODS We characterized the number and density of calretinin-immunoreactive neurons in the lateral, medial, ...

Galanin coexists with ACh in the basal forebrain and medial septal region. The present study investigated the interactions of the muscarinic receptor antagonist scopolamine and the neuropeptide galanin on an operant spatial delayed nonmatching to sample task (DNMTS) in rats. Scopolamine administered both intraperitoneally and microinjected into the medial septum impaired performance on DNMTS. G...