ABSTRACT
El autor destaca la importancia de la experiencia táctil como estímulo del desarrollo y la adaptación social del ser humano, a partir de la vida intrauterina. Subraya la influencia del contacto con otro ser humano y diferencia sus afectos positivos o negativos en función de la sensibilidad del niño en etapas muy tempranas
Subject(s)
Humans , Animals , Infant, Newborn , Infant , Touch/physiology , Physical Stimulation , Maternal Deprivation , Ornithine Decarboxylase/physiology , Ornithine Decarboxylase , Stress, Physiological/physiopathology , Touch/immunology , Infant, Premature/immunology , Endorphins/biosynthesis , Child Development , Immune System/physiology , Mother-Child RelationsABSTRACT
Rats were trained in a step-down inhibitory avoidance task and retrieval was measured during a test session conducted 24 h after training. The ip administration of a low dose of gamma-endorphin (0.2 microng/kg) immediately after training reduced retrieval time from 40.6 to 13.5 s (N = 15). Higher doses of gamma-endorphin given 5 min before testing (1.0 microng/kg) or immediately after training (5 microng/kg) enhanced retrieval time from 38.6 to 300 s (N = 15) and from 40.6 to 104.4 s (N = 15). All of these effects were either after training or before testing had no effect on retrieval. Since at least the amnestic effect of gamma-endorphin is similar to that of beta-endorphin, and gamma-endorphin is a possible metabolite of beta-endorphin by limited proteolysis of the carboxyl-terminal amino acid, it is suggested that at least some effects of beta-endorphin on memory may be mediated by its proteolysis product, gamma-endorphin
Subject(s)
Rats , Animals , Male , Avoidance Learning , Endorphins/pharmacology , Escape Reaction , Retention, Psychology , Amnesia/chemically induced , Analysis of Variance , Cerebrum/metabolism , Endorphins/biosynthesis , Rats, Inbred StrainsABSTRACT
Os estudos desenvolvidos nos últimos anos, levaram a um rápido avanço nos conhecimentos do papel fisiológico e fisiopatológico dos Peptídeos Opióides Endógenos. Sabemos que estes peptídeos derivam de três precursores, nominalmente proopiomelanocortina, proencefalinas A e B, originando três grupos de substâncias, que têm em comum atividade semelhante aos derivados do ópio. Agem através de seis receptores de membrana denominados pelas letras gregas: mi, delta, capa, sigma, lambda e épsilo. Têm açöes no sistema endócrino, exercendo um controle inibitório sobre a secreçäo de TSH, e do LH, e estimulatório sobre a secreçäo de ADH, da oxitocina, do ACTH, da prolactina e do hormônio de crescimento. Participam também do metabolismo dos carbo-hidratos e na regulaçäo do apetite