the mechanism by which lead may cause a perturbotion in the nevous system is through the nitric oxide synthase. in this study the effect of lead acetate on the hippocampal constitutive nitric oxide production was studied. the variation in the nitric oxide production may contribute to physiological lead neurotoxicity in vivo. different concentrations of lead acetate (10-9 to 10-6 m), wre added t...

Functional magnetic resonance imaging has demonstrated reorganization of memory encoding networks within the temporal lobe in temporal lobe epilepsy, but little is known of the extra-temporal networks in these patients. We investigated the temporal and extra-temporal reorganization of memory encoding networks in refractory temporal lobe epilepsy and the neural correlates of successful subsequen...

Septo-hippocampal cholinergic fibres ramify extensively throughout the hippocampal formation to release acetylcholine upon a diverse range of muscarinic and nicotinic acetylcholine receptors that are differentially expressed by distinct populations of neurones. The resultant modulation of cellular excitability and synaptic transmission within hippocampal circuits underlies the ability of acetyl...

the cholinergic and gabaergic .bers of the medial septal/diagonal band of broca (ms/db) area project to the hippocampus and constitute the septo-hippocampal pathway, which has been proven to play a role in learning and memory. in addition, the hippocampus has bidirectional connections with the septum so that to self-regulate of cholinergic input. the activity of septal and hippocampal neurons i...

The spike discharge of hippocampal excitatory principal cells, also called "place cells," is highly location specific, but the discharge of local inhibitory interneurons is thought to display relatively low spatial specificity. Whereas in other brain regions, such as sensory neocortex, the activity of interneurons is often exquisitely stimulus selective and directly determines the responses of ...

BACKGROUND Hippocampal formation (HF) volume and episodic memory performance are substantially heritable, but HF subregion heritability estimates and their possible shared genetic variance with episodic memory performance remain to be determined. METHODS AND FINDINGS This study provides heritability estimates for hippocampal subregions (e.g, Cornu Amonis, Subiculum, Parasubiculum, Molecular a...

Can neurons induce surrounding glia to provide a more favorable microenvironment? Synapses and nerve growth cones have been showr. to release neurotransmitters (Hume et al. Nature 1983;305:632-634; Kater et al. Trends Neurosci. 1988;11:315-321; Young and PooNuture 1983;305:634-637) providing a possible mechanism for this type of control. The excitatory neurotransmitter glutamate induces an incr...

Little is known of the course and distribution of blood vessels supplying and draining the hippozampus. Such information could be of value in designing and evaluating lesion and ablation experiments and may reflect spatial properties of neurons. This study mapped the distribution of major arteries and veins of the rat hippocampal formation. Arteries and veins of adult female Wistar rats anesthe...

The postnatal development of the human hippocampal formation (HF) is subject of increasing interest due to its implication in important pathologies that hamper the normal development of children. In this work, we present a glimpse of the main events that constitute important milestones in the development and shaping of some of the most important psychological capabilities such as autobiographic...