PubMed Health⌕ Search

Biomedical subjects

L L Boyarsky

Publications and source records attributed to L L Boyarsky.

16 recordsLinked to original sources

The effect of transmitter antagonists on phasic respiratory neurons.

The activity of inspiratory neurons in the nucleus tractus solitarius (NTS) and of expiratory neurons in the nucleus retroambigualis (RNA) was recorded during the iontophoresis of L-glutamate, bicuculline, and strychnine in chloralose-urethane-anesthetized cat. Bicuculline methoxide caused increased activity of NTS and NRA neurons during their active or burst phases. Neither bicuculline nor strychnine caused increased activity during the silent phases of NTS or NRA neurons. When neurons were driven to fire during their silent phase by L-glutamate, the application of bicuculline methoxide caused a diminution of the evoked activity. It is concluded that both inspiratory and expiratory neurons receive inhibitory inputs during both their active and silent phases. Gamma-aminobutyric acid appears to be gating both the excitatory and inhibitory information to NTS and NRA neurons. Strychnine was generally ineffective in changing the firing patterns of inspiratory and expiratory neurons suggesting a limited role of glycine, taurine, and L-alanine in the respiratory network.

Animals↗

Effects of excitatory and inhibitory amino acids on phasic respiratory neurons.

The responsiveness of phasically active brainstem respiratory neurons to several amino acids was investigated in cats under Dial anesthesia. Four-barreled microelectrodes were used to extrude iontophoretically the putative neurotransmitters L-glutamate, L-asparatate, glycine, and gamma-aminobutyric acid (GABA), L-glutamate and L-aspartate caused increased activity when applied to either inspiratory or expiratory neurons and appeared to be equal in efficacy. Likewise, GABA and glycine depressed ongoing phasic neural activity of both inspiratory and expiratory units. In this case, however, the dosage of GABA required to produce a given depression was significantly less than the required dosage of glycine. These findings support the hypothesis that L-glutamate and/or L-aspartate may act as excitatory neurotransmitter agents at the synapses of brainstem respiratory neurons and conversely, GABA may act as the natural inhibitory neurotransmitter.

Amino Acids↗