Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/prevención & control , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Antiinfecciosos/uso terapéutico , Profilaxis Antibiótica/estadística & datos numéricos , Bacteriemia/prevención & control , Ciprofloxacina/uso terapéutico , Infecciones por Salmonella/prevención & control , Adulto , Anciano , Terapia Antirretroviral Altamente Activa , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recurrencia , Factores de RiesgoRESUMEN
We recorded 18 single cells in the granule cell layer of the cat. Each single cell was screened and identified as a granule cell based on a set of criteria derived from known electrophysiological properties of granule cells. We then monitored the effects of nitrous oxide on the spontaneous activities and the auditory responses of these cells. Nitrous oxide consistently caused a severe inhibition of spontaneous activities as well as responses to sound in these cells. Furthermore, the amplitudes of their action potentials decreased during the inhibition. Three of the 18 cells were subsequently injected intracellularly with HRP. All three were verified to be granule cells. In those granule cells we recorded intracellularly, nitrous oxide did not change the resting membrane potentials. The gradual decrease in the amplitudes of action potentials suggested that some of the mechanisms leading to the genesis of action potentials were being altered by nitrous oxide. It is also possible that nitrous oxide may act on synaptic transmission at a site located postsynaptically on the granule cells.
Asunto(s)
Cerebelo/efectos de los fármacos , Electroencefalografía/efectos de los fármacos , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Óxido Nitroso/farmacología , Estimulación Acústica , Animales , Gatos , Cerebelo/citología , Peroxidasa de Rábano Silvestre , Microelectrodos , Microinyecciones , Neuronas/efectos de los fármacos , Células de Purkinje/efectos de los fármacosRESUMEN
We found in urethane-anesthetized rats that thalamic reticular (TR) cells responding to an electrical stimulus of the optic tract (OT) can be further subdivided into two types, viz. S- and L-type cells. S-type cells, which were selectively excited from area 17 of the visual cortex, were characterized by short latency responses (2.3-6.1 ms) to OT stimulation. TR cells activated antidromically from the dorsal lateral geniculate nucleus were all classified as S-type. Long OT latencies (5.2-15.3 ms) and selective excitation from area 18a were peculiar to L-type cells, which showed antidromic responses to the lateral posterior nucleus stimulation. Mapping studies documented that cells belonging to each type were segregated in the thalamic reticular nucleus; L-type cells were located in the most posterior part. It is suggested that S- and L-type cells are inhibitory interneurons modulating activity of geniculocortical and extrageniculocortical projection cells, respectively.