ACTH 4-9 analog can retard spatial alternation learning in brain damaged and normal rats.
Thirty adult male hooded rats (Long-Evans strain) were assigned randomly to one of three lesion groups (n = 10) and prepared with medial frontal, posterior parietal, or sham neocortical injuries. Following a recovery interval of 10-12 days, access to water was limited to 30 min per day and the rats were shaped to traverse a T-maze for a reward of sweetened water. After a pretraining criterion was attained, osmotic minipumps (Alzet 2002) were installed subcutaneously. The minipumps delivered chronically for the next 14 to 15 days either 0 or 1.2 micrograms of ACTH 4-9 dissolved in bacteriostatic saline per day while the rats were trained on a reinforced spatial alternation task. Analysis of the number of errors made to a criterion of at least 80% correct alternations in two consecutive training sessions, or a ceiling of 62 errors (attained by two rats with parietal lesions), revealed that learning was impaired in the rats with parietal injuries. Contrary to our hypothesis, animals receiving ACTH 4-9 committed more errors than their counterparts receiving only saline.
McDaniel
W F
WF
Department of Psychology, Georgia College, Milledgeville 31061.
Davall
E J
EJ
Walker
P E
PE
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D001925:Brain Damage, Chronic / Q000188:drug therapy*; D001931:Brain Mapping; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005625:Frontal Lobe / Q000187:drug effects*; D008297:Male; D011939:Mental Recall / Q000187:drug effects; D009042:Motivation; D009416:Nerve Regeneration / Q000187:drug effects*; D009949:Orientation / Q000187:drug effects*; D010296:Parietal Lobe / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D012153:Retention, Psychology / Q000187:drug effects
D010446:Peptide Fragments; C028024:ACTH (4-9); D000324:Adrenocorticotropic Hormone