Investigating the influence of LH-projecting BLA neurons upon motivated behavioral responding and appetitive learning

Abstract

To optimize survival, organisms must be able to learn contingencies between external stimuli and rewards and appropriately respond to these associations. Deficits in reward-related learning or reward-seeking are thought to occur in a host of psychopathologies, including depression (Drevets, 2001), eating disorders (Wagner et al., 2007), and substance abuse (Wrase et al., 2007), such that improved understanding of reward processing could potentially aid in the development of therapies. Two neural regions, the basolateral amygdala (BLA) and lateral hypothalamus (LH), are both implicated in reward processing (Adamantidis et al., 2007; Anand and Brobeck, 1951; Brobeck, 1946; Gutierrez et al., 2011; Hoebel and Teitelbaum, 1962; Kempadoo et al., 2013; Margules and Olds, 1962; Muramoto et al., 1993; Sakurai, 2007; Schoenbaum et al., 1998; Tye and Janak, 2007; Tye et al., 2008, 2010), but the role of the BLA's projection to LH in appetitive conditioning and reward-seeking remains unclear. Through the use of optogenetic techniques in mice, I have investigated the influence of LH-projecting BLA neurons upon motivated behavioral responding, which has indicated that the projection may support intracranial self-stimulation (ICSS). Further experiments with in vivo extracellular electrophysiological recordings from LH-projecting BLA neurons may also shed light on the encoding properties of these neurons during appetitive learning.