The development of heart rate responses to weak and strong shock in the preweaning rat.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D001341:Autonomic Nervous System / Q000502:physiology; D002490:Central Nervous System / Q000254:growth & development; D004562:Electrocardiography; D004597:Electroshock; D006339:Heart Rate; D009949:Orientation; D051381:Rats; D012018:Reflex; D013997:Time Factors