| Abstract: | The fluorescence intensity of the catecholamine cell bodies of the A2 group--as determined by microfluorimetry--increased significantly due to exposure of the rats to the following environmental events: placement of a rat from the colony cage into a cold (4 degree C) room for a period of 10 min, isolation of a rat from the colony for 6--7 days, and satiation of gouped rats by allowing them access to sweetened milk for 15 min. The following events failed to affect the intensity of the cells of A2: reduction of the group colony size from eight to three rats per colony for 6--7 days and presentation of water instead of milk after the rats had experienced 6--7 days of milk satiation. These results indicate that aversive as well as rewarding environmental events activate the catecholamine cells of A2. |
