Limits...
The role of the lateral hypothalamus and orexin in ingestive behavior: a model for the translation of past experience and sensed deficits into motivated behaviors.

Hurley SW, Johnson AK - Front Syst Neurosci (2014)

Bottom Line: The LHA also receives inputs from brain areas involved in reward-related learning and orexin neuron activation can become conditioned to environmental stimuli that are associated with rewards.In turn, this information is "fed into" mesolimbic circuitry to influence the performance of motivated behaviors.This hypothesis may foster experiments that will result in an improved understanding of LHA function.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Iowa Iowa City, IA, USA.

ABSTRACT
The hypothalamus has been recognized for its involvement in both maintaining homeostasis and mediating motivated behaviors. The present article discusses a region of the hypothalamus known as the lateral hypothalamic area (LHA). It is proposed that brain nuclei within the LHA including the dorsal region of the lateral hypothalamus (LHAd) and perifornical area (PeF) provide a link between neural systems that regulate homeostasis and those that mediate appetitive motivated behaviors. Functional and immunohistochemical data indicate that the LHA promotes many motivated behaviors including food intake, water intake, salt intake, and sexual behavior. Anatomical tracing experiments demonstrate that the LHA is positioned to receive inputs from brain areas involved in regulating body fluid and energy homeostasis. Regions within the LHA send dense projections to the ventral tegmental area (VTA), providing a pathway for the LHA to influence dopaminergic systems generally recognized to be involved in motivated behaviors and their reinforcement. Furthermore, the LHA contains neurons that synthesize orexin/hypocretin, a neuropeptide that promotes many appetitive motivated behaviors. The LHA also receives inputs from brain areas involved in reward-related learning and orexin neuron activation can become conditioned to environmental stimuli that are associated with rewards. Therefore, it is hypothesized that the LHA integrates signaling from areas that regulate body fluid and energy balance and reward-related learning. In turn, this information is "fed into" mesolimbic circuitry to influence the performance of motivated behaviors. This hypothesis may foster experiments that will result in an improved understanding of LHA function. An improved understanding of LHA function may aid in treating disorders that are associated with an excess or impairment in the expression of ingestive behavior including obesity, anorexia, impairments in thirst, salt gluttony, and salt deficiency.

No MeSH data available.


Related in: MedlinePlus

A schematic summary of the reviewed experiments. Areas involved in associative learning (green) and maintaining homeostasis (blue) project to the LHA. The LHA sends projections to motivation and reward areas (red) to initiate motivated behaviors. The LHA also sends projections to the nucleus accumbens that may promote motivated behaviors (dashed line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4230038&req=5

Figure 3: A schematic summary of the reviewed experiments. Areas involved in associative learning (green) and maintaining homeostasis (blue) project to the LHA. The LHA sends projections to motivation and reward areas (red) to initiate motivated behaviors. The LHA also sends projections to the nucleus accumbens that may promote motivated behaviors (dashed line).

Mentions: The reviewed experiments support the hypothesis that the LHA contributes to the integration of information related to homeostatic state and past experience with motivation and reward systems. A summary of the anatomical and functional data is presented in Figure 3. Nuclei within the LHA, including the PeF and LHAd, receive projections from brain areas that regulate energy and body fluid homeostasis in addition to areas involved in associative learning (Broberger et al., 1998; Petrovich et al., 2005; Hurley et al., 2013a). In turn, these areas of the LHA send projections to the VTA where they promote motivated behaviors, at least partially through the release of orexin in the VTA (Phillipson, 1979; Fadel and Deutch, 2002; Geisler and Zahm, 2005). Although Figure 3 displays a hierarchical model of LHA functioning dominated by efferent connections to downstream brain areas, it may be the case that this circuitry is actually a neural network which consists of bidirectional inputs between areas involved in learning, homeostasis, and motivation and reward. In this respect, the use of anterograde and retrograde tracer co-injections would provide utility in identifying whether these areas form a neuronal network (for example see Thompson and Swanson, 2010).


The role of the lateral hypothalamus and orexin in ingestive behavior: a model for the translation of past experience and sensed deficits into motivated behaviors.

Hurley SW, Johnson AK - Front Syst Neurosci (2014)

A schematic summary of the reviewed experiments. Areas involved in associative learning (green) and maintaining homeostasis (blue) project to the LHA. The LHA sends projections to motivation and reward areas (red) to initiate motivated behaviors. The LHA also sends projections to the nucleus accumbens that may promote motivated behaviors (dashed line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230038&req=5

Figure 3: A schematic summary of the reviewed experiments. Areas involved in associative learning (green) and maintaining homeostasis (blue) project to the LHA. The LHA sends projections to motivation and reward areas (red) to initiate motivated behaviors. The LHA also sends projections to the nucleus accumbens that may promote motivated behaviors (dashed line).
Mentions: The reviewed experiments support the hypothesis that the LHA contributes to the integration of information related to homeostatic state and past experience with motivation and reward systems. A summary of the anatomical and functional data is presented in Figure 3. Nuclei within the LHA, including the PeF and LHAd, receive projections from brain areas that regulate energy and body fluid homeostasis in addition to areas involved in associative learning (Broberger et al., 1998; Petrovich et al., 2005; Hurley et al., 2013a). In turn, these areas of the LHA send projections to the VTA where they promote motivated behaviors, at least partially through the release of orexin in the VTA (Phillipson, 1979; Fadel and Deutch, 2002; Geisler and Zahm, 2005). Although Figure 3 displays a hierarchical model of LHA functioning dominated by efferent connections to downstream brain areas, it may be the case that this circuitry is actually a neural network which consists of bidirectional inputs between areas involved in learning, homeostasis, and motivation and reward. In this respect, the use of anterograde and retrograde tracer co-injections would provide utility in identifying whether these areas form a neuronal network (for example see Thompson and Swanson, 2010).

Bottom Line: The LHA also receives inputs from brain areas involved in reward-related learning and orexin neuron activation can become conditioned to environmental stimuli that are associated with rewards.In turn, this information is "fed into" mesolimbic circuitry to influence the performance of motivated behaviors.This hypothesis may foster experiments that will result in an improved understanding of LHA function.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Iowa Iowa City, IA, USA.

ABSTRACT
The hypothalamus has been recognized for its involvement in both maintaining homeostasis and mediating motivated behaviors. The present article discusses a region of the hypothalamus known as the lateral hypothalamic area (LHA). It is proposed that brain nuclei within the LHA including the dorsal region of the lateral hypothalamus (LHAd) and perifornical area (PeF) provide a link between neural systems that regulate homeostasis and those that mediate appetitive motivated behaviors. Functional and immunohistochemical data indicate that the LHA promotes many motivated behaviors including food intake, water intake, salt intake, and sexual behavior. Anatomical tracing experiments demonstrate that the LHA is positioned to receive inputs from brain areas involved in regulating body fluid and energy homeostasis. Regions within the LHA send dense projections to the ventral tegmental area (VTA), providing a pathway for the LHA to influence dopaminergic systems generally recognized to be involved in motivated behaviors and their reinforcement. Furthermore, the LHA contains neurons that synthesize orexin/hypocretin, a neuropeptide that promotes many appetitive motivated behaviors. The LHA also receives inputs from brain areas involved in reward-related learning and orexin neuron activation can become conditioned to environmental stimuli that are associated with rewards. Therefore, it is hypothesized that the LHA integrates signaling from areas that regulate body fluid and energy balance and reward-related learning. In turn, this information is "fed into" mesolimbic circuitry to influence the performance of motivated behaviors. This hypothesis may foster experiments that will result in an improved understanding of LHA function. An improved understanding of LHA function may aid in treating disorders that are associated with an excess or impairment in the expression of ingestive behavior including obesity, anorexia, impairments in thirst, salt gluttony, and salt deficiency.

No MeSH data available.


Related in: MedlinePlus