Figure 1.

Experiment 1: the effects of intravenously infusing panic-prone rats (ie, with previous infusions of the GABA synthesis inhibitor (-allylglycine: -AG) into the dorsomedial hypothalamus (DMH)) with hypertonic (0.5 M) -mannitol, sodium chloride (NaCl), or sodium lactate (NaLac) on ‘anxiety'- and ‘flight'-associated behavior and cardiovascular responses. (a) Illustration of osmotic minipump placements in the DMH from −3.30 to −2.80 mm from the bregma. Black circles represent histological placements of the minipumps residing in the DMH in which the l-AG infusions occurred. The bar graph in (b) illustrates the effects of the different i.v. infusions on the duration of social interaction (SI) in an open field as compared with pre-l-AG baseline data. Line graphs illustrate changes in (c) general activity counts, (d) heart rate (HR in beats/min (BPM)) comparing baseline values (pre-i.v. infusion) with values measured post-i.v. infusion, and (e) mean arterial blood pressure (MAP in mm Hg). There was no significant baseline HR, MAP, or activity between groups (see the legends in the figures with baseline HR, MAP and activity ± SEM). Values of bars or lines represent the mean, whereas error bars represent SEM. Mean values of baseline MAP, RR, and HR+SEM are listed in the legend for each group. Abbreviations: 3V, third ventricle; f, fornix; mt, mammillothalamic tract, PeF, perifornical nucleus.