The effects of uniform steady state (DC) extracellular electric fields on neuronal excitability were characterized in rat hippocampal slices using field, intracellular and voltage-sensitive dye recordings. Small electric fields (</40/ mV mm(-1)), applied parallel to the somato-dendritic axis, induced polarization of CA1 pyramidal cells; the relationship between applied field and induced polariz...

The beta-adrenoceptor-blocking and class III effects of sotalol were assessed in 11 patients with inducible orthodromic reciprocating tachycardia. Serum sotalol concentration, maximum exercise heart rate, and electrophysiologic study data were obtained at control, at the beta-adrenoceptor-blocking dosage (407 +/- 149 mg/day, 1.4 +/- 0.5 micrograms/ml), and at the maximum well-tolerated dosage (...

1. Neurons in the cochlear nucleus, nucleus magnocellularis (NM), of embryonic and neonatal chicks are dependent on eighth nerve activity for their maintenance and survival. Removing this input results in the death of 20-40% of the NM neurons and profound changes in the morphology and metabolism of surviving neurons. 2. One of the first changes in NM neurons after an in vivo cochlea removal is ...

1. Single-electrode current- and voltage-clamp techniques were employed to study properties of the conductance underlying an orthodromically evoked late synaptic hyperpolarization or late inhibitory postsynaptic potential (IPSP) in CA3 pyramidal neurons in the rat hippocampal slice preparation. 2. Late IPSPs could occur without preceding excitatory postsynaptic potentials at the resting membran...

Intracellular recording techniques were used to study electrical activity in bipolar sensory cells associated with crayfish tactile receptors. Several lines of evidence indicate that spikes evoked by natural stimulation of the receptor originate at a dendritic locus. Although overshooting spikes are recorded in the soma in response to both natural and antidromic stimulation receptor potentials ...

The apical dendrites of CA1 pyramidal cells were isolated from their cell bodies by making cuts through proximal stratum radiatum of transverse hippocampal slices from the guinea pig. This lesion separated the distal apical dendritic elements from the somata, basal dendrites, and 50 to 100 microns of the proximal apical dendritic tree. Orthodromic stimuli in stratum radiatum evoked excitatory s...

We obtained rat brain slices (550-650 microm) that contained part of the frontoparietal cortex along with a portion of the thalamic ventrobasal complex (VB) and of the reticular nucleus (RTN). Maintained reciprocal thalamocortical connectivity was demonstrated by VB stimulation, which elicited orthodromic and antidromic responses in the cortex, along with re-entry of thalamocortical firing orig...

The role of the substantia innominata (SI) in the generation of a behavior mediated by the prefrontal (PF) cortex was examined in two Japanese monkeys. PF neuronal activities related to a visual tracking task by wrist movement were recorded and neural responses to SI stimulation were analyzed. Sixty-six neurons showed task-related activity and were classified into 3 types. Type 1 (n = 31) showe...

Suprathreshold corticostriatal responses recorded from medium spiny neurons (MSNs) from the direct and indirect pathways of the basal ganglia are different. Their differences readily distinguish D(1)- and D(2)-type receptor expressing MSNs in both bacterial artificial chromosome-transgenic mice and their control littermates as well as in rats: indirect pathway neurons are more excitable than di...