Efferent projections of the basolateral amygdala in the opossum, Didelphis virginiana

McDonald, Alexander J.; Culberson, James L.

doi:10.1016/0361-9230(86)90238-8

Cited by 25 publications

(14 citation statements)

References 66 publications

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“…1 A, B). Because BLA outputs are predominantly ipsilateral (McDonald and Culberson, 1986;Swanson and Petrovich, 1998), this preparation disconnected the BLA and LHA in both hemispheres (contralateral group, n ϭ 14 animals with acceptable lesions) without disturbing other functional circuits involving each of these structures. A control group of rats (ipsilateral group, n ϭ 12 animals with acceptable lesions) had an equivalent amount of damage with unilateral lesions of BLA and LHA placed on the same side of the brain, sparing the BLA-LHA system in one hemisphere.…”

Section: Results Histologymentioning

confidence: 99%

Amygdalo-Hypothalamic Circuit Allows Learned Cues to Override Satiety and Promote Eating

et al. 2002

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Organisms eat not only in a response to signals related to energy balance. Eating also occurs in response to "extrinsic," or environmental, signals, including learned cues. Such cues can modify feeding based on motivational value acquired through association with either rewarding or aversive events. We provide evidence that a specific brain system, involving connections between basolateral amygdala and the lateral hypothalamus, is crucial for allowing learned cues (signals that were paired with food delivery when the animal was hungry) to override satiety and promote eating in sated rats. In an assessment of second-order conditioning, we also found that disconnection of this circuitry had no effect on the ability of a conditioned cue to support new learning. Knowledge about neural systems through which food-associated cues specifically control feeding behavior provides a defined model for the study of learning that may be informative for understanding mechanisms that contribute to eating disorders and more moderate forms of overeating.Key words: amygdala; hypothalamus; eating; feeding behavior; learning; goal-directed behavior; motivation Mild to severe obesity, estimated to affect ϳ60% of the adult population in developed countries, is a risk factor for a range of diseases (United States Department of Health and Human Services, 1999). Despite adverse health consequences, difficulties in achieving and maintaining weight control are common. Overeating is attributable, at least in part, to the fact that food consumption is powerfully influenced by a variety of environmental factors that are unrelated to energy requirements (Rodin, 1981;Booth, 1989). Eating can be socially facilitated (De Castro, 1997), and cues that become associated with food when hunger prevails can increase eating in satiated states (Weingarten, 1983).Recent research is beginning to define the neural systems through which such psychological processes influence eating. Under conditions that strongly potentiate feeding, laboratory rats with neurotoxic lesions of the basolateral amygdalar area (BLA) [including basolateral ("basal"), basomedial ("accessory basal"), and lateral nuclei] fail to increase eating in the presence of a conditioned stimulus (CS) that was previously paired with food (Gallagher, 2000;Holland et al., 2002). The BLA has anatomical connections with neural circuits in the hypothalamus that control feeding behavior (Elmquist et al., 1999;Swanson, 2000;DeFalco et al., 2001;Petrovich et al., 2001). It sends substantial, topographically organized projections to the lateral hypothalamic area (LHA) (Petrovich et al., 2001), which forms part of the feeding circuit and historically has been linked to initiation of feeding (Elmquist et al., 1999).The current investigation examined potentiation of feeding by a CS in rats with a preparation that disconnects the BLA and the LHA. Here we report that the BLA-LHA system is crucial for allowing learned cues to override satiety signals and stimulate eating in sated states. We further show that t...

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Section: Results Histologymentioning

confidence: 99%

Amygdalo-Hypothalamic Circuit Allows Learned Cues to Override Satiety and Promote Eating

et al. 2002

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“…The nodes in this case were the BLA and the hypothalamus, which were defined using the same masks as described above and, as informed by the BOLD results, restricted to the right hemisphere only. Only ipsilateral connections were investigated because crossed connections between the amygdala and hypothalamus are rare (Ottersen and Ben-Ari, 1979;McDonald and Culberson, 1986). The first eigenvariate of the time series was extracted at the single-subject level for right BLA and hypothalamus ROIs.…”

Section: Methodsmentioning

confidence: 99%

Basolateral Amygdala Response to Food Cues in the Absence of Hunger Is Associated with Weight Gain Susceptibility

et al. 2015

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In rodents, food-predictive cues elicit eating in the absence of hunger (Weingarten, 1983). This behavior is disrupted by the disconnection of amygdala pathways to the lateral hypothalamus (Petrovich et al., 2002). Whether this circuit contributes to long-term weight gain is unknown. Using fMRI in 32 healthy individuals, we demonstrate here that the amygdala response to the taste of a milkshake when sated but not hungry positively predicts weight change. This effect is independent of sex, initial BMI, and total circulating ghrelin levels, but it is only present in individuals who do not carry a copy of the A1 allele of the Taq1A polymorphism. In contrast, A1 allele carriers, who have decreased D2 receptor density (Blum et al., 1996), show a positive association between caudate response and weight change. Regardless of genotype, however, dynamic causal modeling supports unidirectional gustatory input from basolateral amygdala (BLA) to hypothalamus in sated subjects. This finding suggests that, as in rodents, external cues gain access to the homeostatic control circuits of the human hypothalamus via the amygdala. In contrast, during hunger, gustatory inputs enter the hypothalamus and drive bidirectional connectivity with the amygdala. These findings implicate the BLA-hypothalamic circuit in long-term weight change related to nonhomeostatic eating and provide compelling evidence that distinct brain mechanisms confer susceptibility to weight gain depending upon individual differences in dopamine signaling.

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“…Despite the abundance of morphological data of the opossum nervous system [16,17,19,23,24,26,27,35,42], the anatomy of the lumbosacral plexus is not widely reported.…”

Section: Introductionmentioning

confidence: 99%

Lumbosacral plexus in Brazilian Common Opossum

et al. 2016

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Efferent projections of the basolateral amygdala in the opossum, Didelphis virginiana

Cited by 25 publications

References 66 publications

Amygdalo-Hypothalamic Circuit Allows Learned Cues to Override Satiety and Promote Eating

Amygdalo-Hypothalamic Circuit Allows Learned Cues to Override Satiety and Promote Eating

Basolateral Amygdala Response to Food Cues in the Absence of Hunger Is Associated with Weight Gain Susceptibility

Lumbosacral plexus in Brazilian Common Opossum

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