Conditioned medium prepared from slices of the rat hippocampal formation contains an agent that shares the following properties with nerve growth factor (NGF): it promotes neurite growth from embryonic sympathetic ganglia in vitro; and it is inhibited by affinity-purified antibody against mouse submaxillary gland 2.5 S NGF. The NGF-like growth-promoting activity is regionally distributed within...

A complete understanding of the hippocampus depends on elucidating the representations and computations that exist in its anatomically distinct subfields. High-resolution structural and functional MRI scanning is starting to permit insights into hippocampal subfields in humans. In parallel, such scanning has facilitated the use of multi-voxel pattern analysis (MVPA) to examine information prese...

The serotonergic and cholinergic neurotransmitter systems interact during processes of learning and memory. Although the effects of aging on cholinergic innervation has been extensively investigated, it is not clear how the serotonergic innervation is altered during aging. The hippocampal formation, a target area of both cholinergic and serotonergic fibers, is a crucial structure for learning a...

Different functions have been suggested for the hippocampus and its subdivisions along both transversal and longitudinal axes. Expression of immediate-early genes (IEGs) has been used to map specific functions onto neuronal activity in different areas of the brain including the hippocampus (IEG imaging). Here we review IEG studies on hippocampal functional dissociations with a particular focus ...

We present a model for neural circuit mechanisms underlying hippocampal memory. Central to this model are nonlinear interactions between anatomically and functionally segregated inputs onto dendrites of pyramidal cells in hippocampal areas CA3 and CA1. We study the consequences of such interactions using model neurons in which somatic burst-firing and synaptic plasticity are controlled by conju...

BACKGROUND Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. METHODOLOGY/PRINCIPAL FINDINGS Here we examined carbachol-induced gamma oscillations in hippocampal slices lacking BDNF gene in the area CA3. The power of oscillations was reduced in the hippocampal area CA1, which coincided w...

Studies of hippocampal long-term potentiation (LTP), a cellular model of memory storage, implicate cAMP-dependent protein kinase (PKA) in presynaptic and postsynaptic mechanisms of LTP. The anchoring of PKA to AKAPs (A kinase-anchoring proteins) creates compartmentalized pools of PKA, but the roles of presynaptically and postsynaptically anchored forms of PKA in late-phase LTP are unclear. In t...

Objective(s):The present study investigated the effect of long-term mild cerebral hypoperfusion induced by permanent unilateral (right) common carotid artery occlusion (UCO) on the dorsal hippocampal neurons in rats. Materials and Methods:Sixty four male Sprague-Dawley rats aged 4 months were divided into two groups of sham and UCO. These two groups were further divided into 4 sets of histopath...

Hippocampal activity in vivo is characterized by concurrent oscillations at theta (4-15 Hz) and gamma (20-80 Hz) frequencies. Here we show that cholinergic receptor activation (methacholine 10-20 nm) in hippocampal slice cultures induces an oscillatory mode of activity, in which the intrinsic network oscillator (located in the CA3 area) expresses simultaneous theta and gamma network oscillation...

The function of the CA3 region of the hippocampus can be explained in terms of a sequence predicting recoder. For the CA3 to act as a neural prediction device, each CA3 neuron must also act as a predictor. Thus, such neurons, as prediction devices, compute something that might approximate a conditional probability. In particular, we conjecture that each neuron forecasts its own firing. Here we ...