ABSTRACT
The present study was undertaken to evaluate the effects of two structurally dissimilar calcium channel blockers, verapamil (a phenylalkylamine) in a single dose of 40 and 80 mg, and nifedipine (a dihydropyridine) in a single dose of 10 and 15 mg, on psychomotor performance and higher mental functions in human volunteers. Placebo and diazepam (5 mg) were used as negative and positive controls respectively. For evaluating these functions, tests employed were arithmetic ability, visual and auditory reaction time, letter (alphabet) cancellation, rapid fire arithmetic deviation and short term memory for playing cards. Careful record was kept of the heart rate, blood pressure and side effects of the therapy, each time the psychomotor tests were performed. Verapamil, both in 40 and 80 mg dose, was found to impair the performance of subjects to a significant extent in auditory reaction time, letter cancellation and short term memory. These effects were similar to those observed with administration of diazepam. With nifedipine, impairment in performance was observed only in rapid arithmetic deviation test. Thus, calcium channel antagonists, specially verapamil, impaired psychomotor performance of human subjects in our study.
Subject(s)
Adult , Blood Pressure/drug effects , Diazepam/pharmacology , Drug Evaluation , Female , Heart Rate/drug effects , Higher Nervous Activity/drug effects , Humans , Male , Nifedipine/administration & dosage , Psychomotor Performance/drug effects , Verapamil/administration & dosageABSTRACT
Uno de los aspectos más relevantes del registro de la actividad unitaria celular en mamíferos, es la localización precisa de los sitios registrados. El asignar a las neuronas o grupos neuronales una colección definida, muchas veces permite establecer la función que estas estructuras tienen en el SNC. Es por esto que hemos desarrollado un método para identificar las neuromas estudiadas, utilizando micropipetas de vidrio que contienen una solución de azul de pontamina al 4% ne KCL 1M. Al finalizar los registros de actividad neuronal unitaria se hace una inyección iontofeorética, se sacrifican los animales, se fijan y se corta el tejido en microtomo de congelación. Se aplica la técnica de procedimiento rápido para obtener una fotografía de la zona de interés. Este método es fácil y rapido de realizar, y tiene la ventaja de que los mismos cortes del tejido pueden ser usados para procedimientos histológicos posteriores