Here we address how dynamics of glutamatergic and GABAergic synaptic input to CA3 pyramidal cells contribute to spontaneous emergence and evolution of recurrent seizure-like events (SLEs) in juvenile (P10-13) rat hippocampal slices bathed in low-[Mg(2+)] artificial cerebrospinal fluid. In field potential recordings from the CA3 pyramidal layer, a short epoch of high-frequency oscillation (HFO; ...

The behaviour-contingent rhythmic synchronization of neuronal activity is reported by local field potential oscillations in the theta, gamma and sharp wave-related ripple (SWR) frequency ranges. In the hippocampus, pyramidal cell assemblies representing temporal sequences are coordinated by GABAergic interneurons selectively innervating specific postsynaptic domains, and discharging phase locke...

The predominant excitatory synaptic input to the hippocampus arises from entorhinal cortical axons that synapse with dentate granule cells, which in turn synapse with CA3 pyramidal cells. Thus, two highly excitable brain areas – the entorhinal cortex and the CA3 field – are separated by dentate granule cells, which have been proposed to function as a gate or filter. However, unlike rats, primat...

In addicts, associative memories related to the rewarding effects of drugs of abuse can evoke powerful craving and drug seeking urges, but effective treatment to suppress these memories is not available. Detailed insight into the neural circuitry that mediates expression of drug-associated memory is therefore of crucial importance. Substantial evidence from rodent models of addictive behavior p...

Intracellular and field potential recordings were taken from the lateral nucleus of the amygdala in a rat horizontal brain slice preparation that included hippocampal formation. Pyramidal cells comprised the majority of labeled cells (77%). Electrophysiological classification based on hyperpolarizing or depolarizing afterpotentials subdivided both the pyramidal and non-pyramidal cell classes, a...

Background: Accurately mapping the pyramidal tracts preoperatively and intraoperatively is the primary concern when operating on cavernous malformations (CMS) in the basal ganglia. We have conducted new methods for preoperative planning and have tailored lesion resection to prevent the damage of pyramidal tracts. Patients and methods: Eleven patients harboring cavernous malformations in basal g...

In pyramidal neurons such as hippocampal area CA1 and basolateral amygdala, a slow afterhyperpolarization (sAHP) follows a burst of action potentials, which is a powerful regulator of neuronal excitability. The sAHP amplitude increases with aging and may underlie age related memory decline. The sAHP is due to a Ca(2+)-dependent, voltage-independent K(+) conductance, the molecular identity of wh...

In order to determine whether pyramidal cells of the adult hippocampus are morphologically sensitive to thyroid hormone, we performed single-section Golgi impregnation analyses on brains from hyperthyroid and control rats. Quantitative analyses of Golgi-impregnated pyramidal cells from the CA1 region showed a significant decrease in the density of apical dendritic spines with hyperthyroidism. I...

Pyramidal cells are the most abundant type of neurons in the cerebral cortex. Their activity has been associated with higher cognitive and emotional functions. Pyramidal cells have a characteristic structure, consisting of a triangularly shaped soma where from two complex dendritic trees and a long bifurcated axon extend. All the morphological components of the pyramidal neurons exhibit signifi...

Experimental mouse chimeras have proven useful in analyzing the cell lineages of various tissues. Here we use experimental mouse chimeras to study cell lineage of the hippocampus. We examined clonal architecture and lineage relationships of the hippocampal pyramidal cells, dentate granule cells, and GABAergic interneurons. We quantitatively analyzed like-genotype cohorts of these neuronal popul...