Integration Of Afferent Signals Research Articles

Reciprocal signaling between adipose tissue depots and the central nervous system.

In humans, various dietary and social factors led to the development of increased brain sizes alongside large adipose tissue stores. Complex reciprocal signaling mechanisms allow for a fine-tuned interaction between the two organs to regulate energy homeostasis of the organism. As an endocrine organ, adipose tissue secretes various hormones, cytokines, and metabolites that signal energy availability to the central nervous system (CNS). Vice versa, the CNS is a critical regulator of adipose tissue function through neural networks that integrate information from the periphery and regulate sympathetic nerve outflow. This review discusses the various reciprocal signaling mechanisms in the CNS and adipose tissue to maintain organismal energy homeostasis. We are focusing on the integration of afferent signals from the periphery in neuronal populations of the mediobasal hypothalamus as well as the efferent signals from the CNS to adipose tissue and its implications for adipose tissue function. Furthermore, we are discussing central mechanisms that fine-tune the immune system in adipose tissue depots and contribute to organ homeostasis. Elucidating this complex signaling network that integrates peripheral signals to generate physiological outputs to maintain the optimal energy balance of the organism is crucial for understanding the pathophysiology of obesity and metabolic diseases such as type 2 diabetes.

Model of the function of the neostriatum and its neuronal activity during behavior in monkeys.

Experiments with simultaneous recording of six neostriatum neurons showed that the neurons of this structure are involved in the organization of all stages of behavior. A defined combination of neuronal activity corresponded to each action of the animal. The responses of individual neostriatal neurons were not entirely determined by the action being carried out at a particular moment, but reflected a wider aspect of the overall activity of the animal. These data, along with the established properties of neuronal responses in the neural network model, indicate that the integration of afferent signals in the neostriatum and their distribution to efferent connections is based on network mechanisms of neuronal interactions.

Hypothalamic cells in an area mediating ACTH release respond to right atrial stretch

The right atrium has been shown to mediate release of ACTH in response to small hemorrhage. Therefore, we sought to identify hypothalamic neurons (cat, alpha-choloralose 35-45 mg/kg) wholse firing rates were modulated by stretch of the right atrial-vena caval junction. Stretch was produced by intermittent inflation of a balloon implanted between the pericardium and the right atrium. In some cases, carotid arteries were occluded bilaterally. Previous results indicate that electrical stimulation of the medial-dorsal hypothalamus (MDH) causes prompt changes in ACTH, but stimulation in the lateral hypothalamus does not cause changes. Of 64 cells recorded in the MDH, 41 responded to atrial stretch. However, only 2 of 18 cells outside this region responded. Six cells were studied with and without carotid occlusion. Their response was dimished or absent in the absence of carotid occlusion. The results suggest that integration of afferent signals from cardiovascular receptors occurs in the MDH and that the MDH may participate in neural mediation of ACTH in response to hemodynamic changes.

The physiology of human penile erection

Abstract Human penile erection depends on integration of afferent signals in the thoracolumbar or sacral erection centers, intact autonomic nerves to the penis, normal erectile tissues, and an adeq...

The physiology of human penile erection.

Abstract Human penile erection depends on integration of afferent signals in the thoracolumbar or sacral erection centers, intact autonomic nerves to the penis, normal erectile tissues, and an adeq...