animal experiment 12 pinealectomy rat 12 Pineal Gland 10 Rats 10 endocrine system 10 Animal 8 Male 8 Rats, Inbred Strains 8 autonomic nervous system 8 central nervous system 8 pineal body 8 superior cervical ganglionectomy 8 Support, Non-U.S. Gov't 6 melatonin 6 pineal gland 6 Female 4 Ganglia, Sympathetic 4 adrenergic system 4 article 4 intraperitoneal drug administration 4 nonhuman 4 progesterone 4 radioisotope 4 subcutaneous drug administration 4 unclassified drug 4 Animals 2 Cerebral Cortex 2 Circadian Rhythm 2 Cyclic AMP 2