We have previously shown that double deletion of the genes for Rac1 and Rac3 GTPases during neuronal development affects late developmental events that perturb the circuitry of the hippocampus, with ensuing epileptic phenotype. These effects include a defect in mossy cells, the major class of excitatory neurons of the hilus. Here, we have addressed the mechanisms that affect the loss of hilar m...

The multiple memory systems hypothesis posits that dorsal striatum and hippocampus are central nodes in independent memory systems, supporting response-based and place-based learning, respectively. Although our understanding of the function of hippocampus within this framework is relatively well established, the contribution of dorsal striatum is less clear. This in part seems to be due to the ...

Available evidence suggests there is functional differentiation among hippocampal and parahippocampal subregions and along the dorsoventral (septotemporal) axis of the hippocampus. The aim of this study was to characterize and compare the efferent and afferent connections of perirhinal areas 35 and 36, postrhinal cortex, and the lateral and medial entorhinal areas (LEA and MEA) with dorsal and ...

We reported previously that the neuropeptide oxytocin attenuates stress-induced hypothalamo-pituitary-adrenal (HPA) activity and anxiety behavior. This study sought to identify forebrain target sites through which oxytocin may mediate its anti-stress effects. Ovariectomized, estradiol-treated rats received intracerebroventricular infusions of oxytocin (1 or 10 ng/hr) or vasopressin (10 ng/hr), ...

This study was designed to determine (1) which brain area paces the theta rhythm in the medial entorhinal cortex (MEC) of rats and (2) the extent to which the behavioral effects of lesions in the medial septal area (MSA), which disrupt the cholinesterase-related pathway to the hippocampal formation, resemble the effects previously reported to result from fimbria-fornix lesions. MSA lesions abol...

In the present study, we have investigated the effects and interaction of CCK and GABAergic systems in the dorsal hippocampus of rats using the elevated plus-maze test of anxiety. Bilateral injection of different doses of CCK(8s) (0.01, 0.05 and 0.1 microg/rat) into the dorsal hippocampus (intra-CA1) decreased percentage of open arm time (%OAT) and open arm entries (%OAE) that are representativ...

Nicotine, an active tobacco derived alkaloid, regulates the activity of the neuronal nitric oxide synthase (nNOS) as well as the release of nitric oxide (NO) in the nervous system. Nicotinic acetylcholine receptors and nNOS are abundantly co-expressed in the hippocampal neurons and are found to alter anxiety-like behaviors in rodents. Dorsal hippocampus may be a site for modulation of anxiety. ...

ii ABSTRACT OF THE THESIS Effects of temporary inactivation of dorsal hippocampus on explicitly nonspatial, Several studies have reported that dorsal hippocampal damage attenuates the of recently acquired contextual fear conditioning. "Context" is often operationalized as the conditioning chamber in which CS-US pairings occurred. However, the hippocampus is known to participate in spatial learn...

According to Gray [The Neuropsychology of Anxiety: An Enquiry into the Functions of the Septo-hippocampal System, Oxford University Press, New York, 1982], the hippocampus and the septum act in concert to control anxiety. We found that micro-infusion of midazolam into the dorsal hippocampus increased rats' open-arm exploration in the elevated plus-maze. Co-infusion of L-glutamate into the septu...

In this study the role of CA1 region of dorsal hippocamus an amygdala kindling rate was investigated by bilateral microinjection of lidocaine into hippocampus.28 rats were divided into four groups.in group I:animals were implanted only with a tripolar electrode into the amygdala but in groups 2-4,two guide cannulaae were also implanted into  the CA1 region of the dorsale hippocampus.two monopol...