Simultaneous somatic and dendritic recordings were made from the same neocortical layer V pyramidal neuron, and current injection via the dendritic recording pipette was used to simulate the voltage change that occurs during an EPSP. At the soma, these simulated EPSPs increased nonlinearly with the amplitude of the dendritic current injection and with depolarization of the membrane potential. B...

Whole cell voltage-clamp recordings were performed on auditory olivocochlear neurons in the ventral nucleus of the trapezoid body (VNTB) of brain stem slices from neonatal rats. Each neuron was identified by retrograde labeling with Fast Blue injected into the cochlea. Bath application of norepinephrine (NE; 1-10 microM) reversibly induced an inward current in 26 of 38 labeled neurons that were...

A common feature of neuronal nicotinic acetylcholine receptors (nAChRs) is that they conduct inward current at negative membrane potentials but little outward current at positive membrane potentials, a property referred to as inward rectification. Physiologically, inward rectification serves important functions, and the main goal of our study was to investigate the mechanisms underlying the rec...

A variety of scorpion venoms and purified toxins were tested for effects on ion channels in human T lymphocytes, a human T leukemia cell line (Jurkat), and murine thymocytes, using the whole-cell patch-clamp method. Nanomolar concentrations of charbdotoxin (CTX), a purified peptide component of Leiurus quinquestriatus venom known to block Ca2+-activated K+ channels from muscle, blocked "type n"...

Pharmacologically distinct calcium channels have been characterized in dissociated cutaneous sensory neurons and motoneurons of the larval lamprey spinal cord. To enable cell identification, sensory dorsal cells and motoneurons were selectively labeled with fluorescein-coupled dextran amine in the intact spinal cord in vitro before dissociation. Calcium channels present in sensory dorsal cells,...

Activation of GABAB receptors in the Xenopus embryo, a simple vertebrate, causes presynaptic inhibition of transmitter release from glycinergic spinal neurons and an increase in action potential threshold. To investigate the underlying mechanisms of GABAB receptor action, we have made whole-cell voltage-clamp recordings from acutely isolated Xenopus embryo spinal neurons. The GABAB receptor ago...

BACKGROUND The effects of lindane, a gamma-isomer of hexachlorocyclohexane, were studied on transmembrane potentials and currents of frog atrial heart muscle using intracellular microelectrodes and the whole cell voltage-clamp technique. RESULTS Lindane (0.34 microM to 6.8 microM) dose-dependently shortened the action potential duration (APD). Under voltage-clamp conditions, lindane (1.7 micr...

The effects of fluoxetine (Prozac), a widely used antidepressant drug, on K+ channel in outer hair cells isolated from guinea pig cochlea were studied using the whole-cell patch clamp technique. Fluoxetine potently inhibited leak K+ currents with an IC50 of 0.78 microM. The inhibition was reversible and voltage-independent. At 45- to 103-fold higher concentrations than the plasma levels, fluoxe...

Abbreviated title: mGluR1-mediated modulation of neuronal excitability Number of words in the Abstract: 298 Number of text pages: 25 Abstract The modulation of neuron excitability by group I metabotropic glutamate receptors (mGluRs) was studied in isolated lamprey spinal cord neurons. At resting potential, application of the group I mGluR agonist (R, S)-3,5-dihydroxyphenylglycine (DHPG) slightl...

Light-evoked changes in membrane voltage were recorded intracellularly from rod photoreceptors in the isolated retina preparation of the toad, Bufo marinus, during superfusion with a solution containing pharmacological agents that blocked voltage-dependent conductances . Under these conditions, the amplitude ofthe hyperpolarizing photoresponse became much greater than under control conditions ....