Intracellular recordings were made in the dorsal hippocampal formation of urethane-anesthetized rats as the local field activity spontaneously cycled between a synchronous condition termed theta and an asynchronous condition termed LIA. All cells reported in this study were labeled with Neurobiotin and classified as theta-related or non-theta-related according to the system of Colom and Bland [...

The CA1 pyramidal neurons in the hippocampus are selectively vulnerable to transient ischemic damage. In experimental animals, the CA1 pyramidal neurons undergo cell death several days after brief forebrain ischemia. It remains, however, unknown whether this delayed neuronal death is necrosis or apoptosis. To investigate the degenerating processes of the CA1 pyramidal neurons in gerbil hippocam...

Synaptic dysfunction is thought to play a major role in memory impairment in Alzheimer's disease (AD). PARP-1 has been identified as an epigenetic regulator of plasticity and memory. Thus, we hypothesize that PARP-1 may be altered in postmortem hippocampus of individuals with AD compared to age-matched controls without neurologic disease. We found a reduced level of PARP-1 nucleolar immunohisto...

Hippocampal pyramidal neurons express three major voltage-dependent potassium currents, IA, ID, and IK. During hippocampal development, IA, the rapidly activating and inactivating transient potassium current, is detected soon after pyramidal neurons can be morphologically identified. Appearance of IA in developing pyramidal neurons is dependent on contact with cocultured astroglial cells; cultu...

Age-related increase in L-type Ca(2+) channel (LTCC) expression in hippocampal pyramidal neurons has been hypothesized to underlie the increased Ca(2+) influx and subsequent reduced intrinsic neuronal excitability of these neurons that lead to age-related cognitive deficits. Here, using specific antibodies against Cav 1.2 and Cav 1.3 subunits of LTCCs, we systematically re-examined the expressi...

Neurons in very low density hippocampal cultures that are physiologically identified as either GABAergic inhibitory or glutamatergic excitatory all contain mRNA for the gamma-aminobutyric acid (GABA) synthetic enzyme, glutamic acid decarboxylase (GAD), as detected by single cell mRNA amplification and PCR. However, consistent with the physiology, immunocytochemistry revealed that only a subset ...

Neurons propagate information through circuits by integrating thousands of synaptic inputs to generate an action potential output. Inputs from different origins are often targeted to distinct regions of a neuron's dendritic tree, with synapses on more distal dendrites normally having a weaker influence on cellular output compared to synapses on more proximal dendrites. Here, we report that hipp...