RESUMEN
Injections of iso- and hypertonic solutions of some potassium salts caused an obvious depolarisation and reduction of electrical resistance in the crayfish slowly adapting stretch receptor neurones' membrane. This response could be eliminated with gadolinium. The stretch-activated channels in the crayfish stretch receptor neurone seem to be affected by an intracellular hydrostatic pressure.
Asunto(s)
Astacoidea/fisiología , Cesio/fisiología , Mecanorreceptores/fisiología , Neuronas/fisiología , Potasio/farmacología , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/fisiología , Mecanorreceptores/citología , Potenciales de la Membrana , Microinyecciones , Neuronas/ultraestructura , Presión , Sales (Química)RESUMEN
Intracellular pressure injection of potassium salt solution has been studied for its effect on the receptor potential of the slowly adapting stretch receptor of crayfish. It was found that the injection caused an increase in the static phase of the receptor potential. The results suggest that the intracellular hydrostatic pressure may be involved in generation of primary receptor responses of mechanoreceptors.
Asunto(s)
Astacoidea/efectos de los fármacos , Mecanorreceptores/efectos de los fármacos , Neuronas/efectos de los fármacos , Animales , Astacoidea/fisiología , Electrofisiología , Técnicas In Vitro , Mecanorreceptores/fisiología , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Microinyecciones/instrumentación , Microinyecciones/métodos , Neuronas/fisiología , Presión , SolucionesRESUMEN
The paper deals with the contribution of intracortical inhibitory processes to the organization of receptive fields in the vibrissae projection area of the somatosensory cortex. Inhibition blockade by means of microelectrophoretic application of picrotoxin and bicucullin was shown to lead to a loss of directional sensitivity of neurones. Activation of inhibition at remote glutamate application led to opposite changes: the neurones became directionally sensitive, and dependence was found between the spatial localization of activated neurones and the character of changes of detector parameters. Inhibitory processes caused by natural afferent stimulation led to similar changes of functional characteristics of neurones.
Asunto(s)
Inhibición Neural , Neuronas/fisiología , Corteza Somatosensorial/fisiología , Vibrisas/fisiología , Vías Aferentes , Animales , Bicuculina/farmacología , Mapeo Encefálico , Gatos , Femenino , Masculino , Estimulación Física , Picrotoxina/farmacología , Corteza Somatosensorial/anatomía & histologíaRESUMEN
Microelectrophoretic application of picrotoxin which is known to reduce inhibition was used for studying inhibitory processes involved in the organization of the sensomotor cortex neurons in cats. The size of the neuronal receptive fields, character of responses and spontaneous activity compared before and after 1 to 3-min application of picrotoxin revealed a considerable enlargening of neuronal receptive fields. The data obtained suggest that inhibition plays a major part in formation of functional properties of neuron.