SHOCK-INDUCED ANALGESIA IN THE COCKROACH (PERIPLANETA-AMERICANA)

For 3 consecutive days cockroaches (Periplaneta americana) received es capable, inescapable, or no shock in an escape task. 24 hr. later mini mum shock which initiated movement was identified. Reliably higher sho cks were needed to initiate movement in the inescapably shocked roache s. In a second experiment the analgesia induced by inescapable shock w as blocked by the opiate antagonist naloxone. The results are discusse d in relation to the escape deficit and analgesia commonly seen follow ing exposure to inescapable shock in a variety of species.