Differential Effects of Dopamine Receptor D1-Type and D2-Type Antagonists and Phase of the Estrous Cycle on Social Learning of Food Preferences, Feeding, and Social Interactions in Mice

Abstract

The neurobiological bases of social learning, by which an animal can 'exploit the expertise of others' and avoid the disadvantages of individual learning, are only partially understood. We examined the involvement of the dopaminergic system in social learning by administering a dopamine D1-type receptor antagonist, SCH23390 (0.01, 0.05, and 0.1 mg/kg), or a D2-type receptor antagonist, raclopride (0.1, 0.3, and 0.6 mg/kg), to adult female mice prior to socially learning a food preference. We found that while SCH23390 dose-dependently inhibited social learning without affecting feeding behavior or the ability of mice to discriminate between differently flavored diets, raclopride had the opposite effects, inhibiting feeding but leaving social learning unaffected. We showed that food odor, alone or in a social context, was insufficient to induce a food preference, proving the specifically social nature of this paradigm. The estrous cycle also affected social learning, with mice in proestrus expressing the socially acquired food preference longer than estrous and diestrous mice. This suggests gonadal hormone involvement, which is consistent with known estrogenic regulation of female social behavior and estrogen receptor involvement in social learning. Furthermore, a detailed ethological analysis of the social interactions during which social learning occurs showed raclopride-and estrous phase-induced changes in agonistic behavior, which were not directly related to effects on social learning. Overall, these results suggest a differential involvement of the D1-type and D2-type receptors in the regulation of social learning, feeding, and agonistic behaviors that are likely mediated by different underlying states.

Acute Cocaine Induces Fast Activation of D1 Receptor and Progressive Deactivation of D2 Receptor Striatal Neurons:In VivoOptical Microprobe [Ca2+]iImaging

“…For the groups in Exp3 (Table 1), the mice were injected (ip) with either D1R antagonist (a bolus dose of 0.075mg/kg SCH23390, Sigma Aldrich) or D2R antagonist (a bolus dose of 3mg/kg raclopride, Sigma Aldrich), which were administrated ip at 30min before cocaine injection in the Drd1-EGFP transgenic mice and Drd2-EGFP transgenic mice, respectively. We chose SCH23390 and raclopride since these are validated antagonists for D1R and D2R respectively, and we selected doses that have been commonly used in preclinical studies (Doherty et al, 2008; Lange et al 2011; Choleris et al 2011; Williams et al 2010). …”

Male risk taking, female odors, and the role of estrogen receptors

“…Both of these actions could influence responses to aversive stimuli and sexually motivated decision making and influence risk taking [122]. In addition, there is evidence that ERs have effects on various aspects of socially, and likely sexually, associated cognitive functions [10,11,88–90,124]. …”

“…Estradiol and ERα and ERβ agonists also exert dose related effects on cognition mediated by regions thought to be involved in learning and decision making (e.g. [124,143]). As well, estrogens influence glutamate transmission within certain nodes of the mesocorticolimbic circuitry that affects DA and decision making [143].…”

Social memories in rodents: Methods, mechanisms and modulation by stress

“…Socially significant cues have been shown to be required for this transmission of food preference; the demonstrator may be anesthetized or sick but not dead (Galef and Wigmore, 1983;Galef, 1985). In addition, exposure to food-powdered cotton alone does not lead to a food preference (Galef et al, 1988;Valsecchi and Galef, 1989) nor does exposure to food odor alone or to a conspecific that did not previously eat the flavored food (Choleris et al, 2011).…”