BRAIN AND BEHAVIOR – HYPOTHALAMUS AND LIMBIC SYSTEM: THE NEUROBIOLOGY OF EMOTIONS

It is intuitive to understand how sensory information gets to the brain and how motor information can travel to the muscles together where these twosystems allow us to detect and respond to the world around us but how do we engage with that world, how do we determine what is important, andhow do we fall in the analysis. These higher cortical functions involve the complex interplay between neurotransmitters and hormones throughout theentire nervous system. There are two major anatomical behaviors; the limbic system and hypothalamus. These structures that support much highercortical functions hypothalamus is a very small structure but it is absolutely critical for life and it allows us to respond to both the internal and externalenvironment and to maintain homeostasis. The limbic system is important for learning and memory, and all emotional aspects of behavior importantlylimbic and hypothalamic structures are interconnected with each other. Let’s begin with an anatomical overview of the hypothalamus in the middlesection. You can delineate the hypothalamus from the thalamus through the hypothalamic sulcus anteriorly, the hypothalamus extends to the anteriorcommissure, and the optic chiasm inferiorly and it includes the mammillary bodies and extends to the infundibula stock where it communicateswith the pituitary glands. It is a coronal section through the brain. It is the third ventricle, you can identify the thalamus on either side of the thirdventricle and underneath; the thalamus is the hypothalamus and it extends laterally to these descending fiber bundles which are part of the internalcapsule. The hypothalamus is structurally part of the diencephalon but it functions as part of the limbic system through reciprocal connections. Ithelps to maintain homeostasis in the entire body through influences on the endocrine system and importantly through its primary influence onboth the sympathetic and parasympathetic systems; the limbic system is extremely old from an evolutionary perspective in its connections and it isinterposed between the hypothalamus and the neocortex and providing a bridge between endocrine visceral emotional and voluntary responses tothe environment.

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General concepts of hypothalamus-pituitary anatomy

Oxford Textbook of Endocrinology and Diabetes ◽

10.1093/med/9780199235292.003.2004 ◽

2011 ◽

pp. 71-81

Author(s):

Ignacio Bernabeu ◽

Monica Marazuela ◽

Felipe F. Casanueva

Keyword(s):

Median Eminence ◽

Third Ventricle ◽

Optic Chiasm ◽

Perivascular Space ◽

Ependymal Cells ◽

The Third ◽

Long Time ◽

Central Grey Matter ◽

Imaginary Line ◽

The Brain

The hypothalamus is the part of the diencephalon associated with visceral, autonomic, endocrine, affective, and emotional behaviour. It lies in the walls of the third ventricle, separated from the thalamus by the hypothalamic sulcus. The rostral boundary of the hypothalamus is roughly defined as a line through the optic chiasm, lamina terminalis, and anterior commissure, and an imaginary line extending from the posterior commissure to the caudal limit of the mamillary body represents the caudal boundary. Externally, the hypothalamus is bounded rostrally by the optic chiasm, laterally by the optic tract, and posteriorly by the mamillary bodies. Dorsolaterally, the hypothalamus extends to the medial edge of the internal capsule (Fig. 2.1.1) (1). The complicated anatomy of this area of the central nervous system (CNS) is the reason why, for a long time, little was known about its anatomical organization and functional significance. Even though the anatomy of the hypothalamus is well established it does not form a well-circumscribed region. On the contrary, it is continuous with the surrounding parts of the CNS: rostrally, with the septal area of the telencephalon and anterior perforating substance; anterolaterally with the substantia innominata; and caudally with the central grey matter and the tegmentum of the mesencephalon. The ventral portion of the hypothalamus and the third ventricular recess form the infundibulum, which represents the most proximal part of the neurohypophysis. A bulging region posterior to the infundibulum is the tuber cinereum, and the zone that forms the floor of the third ventricle is called the median eminence. The median eminence represents the final point of convergence of pathways from the CNS on the peripheral endocrine system and it is supplied by primary capillaries of the hypophyseal portal vessels. The median eminence is the anatomical interface between the brain and the anterior pituitary. Ependymal cells lining the floor of the third ventricle have processes that traverse the width of the median eminence and terminate near the portal perivascular space; these cells, called tanycytes, provide a structural and functional link between the cerebrospinal fluid (CSF) and the perivascular space of the pituitary portal vessels. The conspicuous landmarks of the ventral surface of the brain can be used to divide the hypothalamus into three parts: anterior (preoptic and supraoptic regions), middle (tuberal region), and caudal (mamillary region). Each half of the hypothalamus is also divided into a medial and lateral zone. The medial zone contains the so-called cell-rich areas with well-defined nuclei. The scattered cells of the lateral hypothalamic area have long overlapping dendrites, similar to the cells of the reticular formation. Some of these neurons send axons directly to the cerebral cortex and others project down into the brainstem and spinal cord.

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Cranial Nerves and Cranial Nerve Nuclei

10.1093/med/9780190237493.003.0005 ◽

2017 ◽

Author(s):

Peggy Mason

Keyword(s):

Cranial Nerve ◽

Cranial Nerves ◽

Sensory Information ◽

Abducens Nerve ◽

Motor Information ◽

Anatomical Arrangement ◽

Cranial Nerve Injuries ◽

Nerve Dysfunction ◽

The Common ◽

The Brain

The functions of cranial nerves, conduits for sensory information to enter and motor information to exit the brain, and the common complaints arising from cranial nerve injuries are described. The modified anatomical arrangement of sensory and motor territories in the brainstem provides a framework for understanding the organization of the cranial nerve nuclei. A thorough grounding in the anatomy of cranial nerves and cranial nerve nuclei allows the student to deduce whether a given set of symptoms arises from a central or peripheral lesion. The near triad, pupillary light reflex, and Bell’s palsy are particularly emphasized. The contributions of the six extraocular muscles to controlling eye position and to potential diplopia are described along with the consequences of oculomotor, trochlear, and abducens nerve dysfunction. The potential for lesions of facial, glossopharyngeal, vagus, and hypoglossal nerves to yield dysphagia and dysarthria are outlined.

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Anatomical identification of the neuroendocrine system in the Nothobranchius furzeri brain

10.1101/2020.10.15.342014 ◽

2020 ◽

Author(s):

Eunjeong Do ◽

Yumi Kim

Keyword(s):

Pineal Gland ◽

Pituitary Gland ◽

Three Dimensional ◽

Endocrine System ◽

Neuroendocrine System ◽

Main Body ◽

Nothobranchius Furzeri ◽

Pituitary Glands ◽

Basic Features ◽

The Brain

AbstractThe hypophysis functions as a central gland of the neuroendocrine system for regulating fundamental body physiology. Upon aging, several hormones produced by the endocrine system are dramatically altered. Recently, Nothobranchius furzeri (the turquoise killifish) has become a popular model for aging studies because of its short lifespan and highly conserved aging phenotypes. However, the anatomical details of the major neuroendocrine system of the killifish have not been investigated so far. In this study, we have identified the pituitary and pineal glands of the turquoise killifish, which are critical components of the brain endocrine system. These two neuroendocrine glands were weakly attached to the main body of the killifish brain. The pineal gland was located on the dorsal part of the brain, while the pituitary gland was located on the ventral part. Brain sections containing pineal and pituitary glands were performed and revealed that cells in both the pituitary and pineal glands are densely placed than any other regions of brain. Further, three-dimensional images both in pineal and pituitary glands were uncovered their distinctive cellular arrangements. Vasopressin intestinal peptide (VIP) was strongly expressed in the neurohypophysis of the pituitary gland. Glial cells were found inside the pineal gland, while astrocytes covered the outside. These findings illustrate basic features of the neuroendocrine system of Nothobranchius furzeri.

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Craniopharyngioma causing bilateral vision loss 4 months after unremarkable magnetic resonance imaging of the brain

Journal of Neurosciences in Rural Practice ◽

10.4103/0976-3147.158770 ◽

2015 ◽

Vol 6 (03) ◽

pp. 392-394

Author(s):

Rainy Betts ◽

Curtis E. Margo ◽

Mitchell Drucker

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Vision Loss ◽

Clinical Course ◽

Third Ventricle ◽

Optic Chiasm ◽

Cystic Mass ◽

Resonance Imaging ◽

Suprasellar Cistern ◽

The Brain

ABSTRACTA 65-year-old man developed bilateral vision loss 4 months after magnetic resonance imaging demonstrated no lesion in the vicinity of the optic chiasm, hypothalamus, and suprasellar tissues. Repeat computed tomography 3 months later showed a predominantly cystic mass of the suprasellar cistern with extension into the anterior third ventricle, which histologically was a craniopharyngioma. The clinical course of this case fuels the controversy whether craniopharyngiomas arise from embryonic rests or can be acquired. From a clinical perspective, it raises questions about when to obtain imaging studies dedicated to the chiasm and the appropriate interval in which a scan should be repeated to exclude structural causes of bilateral vision loss.

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Puberty, Hormones, and the Social Brain

Coming of Age ◽

10.1093/oso/9780195314373.003.0006 ◽

2019 ◽

pp. 69-95

Author(s):

Cheryl L. Sisk ◽

Russell D. Romeo

Keyword(s):

Social Cognition ◽

Sensory Information ◽

Social Behaviors ◽

Gonadal Hormones ◽

Sensitive Period ◽

The Social ◽

History Of ◽

Brain And Behavior ◽

And Behavior ◽

The Brain

This chapter begins with some history of the field of behavioral neuroendocrinology and traces the origins of the classic organizational-activational hypothesis to explain sexual differentiation of the brain and behavior and hormonal influences on sex-typical social behaviors. The classic hypothesis posits that testicular hormones masculinize and defeminize neural circuits during a perinatal sensitive period, programming sex-typical activational responses to gonadal hormones in adulthood. Research since the mid- to late 1980s shows that a second wave of hormone-dependent organization of the brain and behavior occurs during puberty and adolescence and that ovarian hormones are actively involved in feminization of the brain during the adolescent period of organization. Next, a conceptual framework is presented for studying adolescent development of social cognition (the mental processes by which an individual encodes, interprets, and responds to sensory information from an animal of the same species) in the context of social reorientation, when during adolescence the source of social reward shifts from family to peers. The chapter reviews the literature on what social behaviors and aspects of social cognition are organized by pubertal hormones in males, as well as the nonsocial behaviors that are organized by pubertal hormones in males and females.

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Relation Between Level of Prefrontal Activity and Subject's Performance

Journal of Psychophysiology ◽

10.1027//0269-8803.13.2.117 ◽

1999 ◽

Vol 13 (2) ◽

pp. 117-125 ◽

Cited By ~ 14

Author(s):

Laurence Casini ◽

Françoise Macar ◽

Marie-Hélène Giard

Keyword(s):

Brain Activity ◽

Sensory Information ◽

Practice Phase ◽

Trained Subjects ◽

Anagram Task ◽

Economic Information ◽

Long Duration ◽

Level Of Activity ◽

The Brain ◽

Processing Mechanism

Abstract The experiment reported here was aimed at determining whether the level of brain activity can be related to performance in trained subjects. Two tasks were compared: a temporal and a linguistic task. An array of four letters appeared on a screen. In the temporal task, subjects had to decide whether the letters remained on the screen for a short or a long duration as learned in a practice phase. In the linguistic task, they had to determine whether the four letters could form a word or not (anagram task). These tasks allowed us to compare the level of brain activity obtained in correct and incorrect responses. The current density measures recorded over prefrontal areas showed a relationship between the performance and the level of activity in the temporal task only. The level of activity obtained with correct responses was lower than that obtained with incorrect responses. This suggests that a good temporal performance could be the result of an efficacious, but economic, information-processing mechanism in the brain. In addition, the absence of this relation in the anagram task results in the question of whether this relation is specific to the processing of sensory information only.

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Review of Self-regulation of the Brain and Behavior.

Contemporary Psychology ◽

10.1037/023440 ◽

1985 ◽

Vol 30 (12) ◽

pp. 999-999

Author(s):

Gerald S. Wasserman

Keyword(s):

Self Regulation ◽

Brain And Behavior ◽

And Behavior ◽

The Brain

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Measuring the World

10.1093/oso/9780198779636.003.0017 ◽

2018 ◽

Author(s):

Ann-Sophie Barwich

Keyword(s):

Sensory Information ◽

Network Models ◽

Model System ◽

Stimulus Input ◽

Expectancy Effects ◽

Neural Network Models ◽

Perceptual Object ◽

External Objects ◽

The Common ◽

The Brain

How much does stimulus input shape perception? The common-sense view is that our perceptions are representations of objects and their features and that the stimulus structures the perceptual object. The problem for this view concerns perceptual biases as responsible for distortions and the subjectivity of perceptual experience. These biases are increasingly studied as constitutive factors of brain processes in recent neuroscience. In neural network models the brain is said to cope with the plethora of sensory information by predicting stimulus regularities on the basis of previous experiences. Drawing on this development, this chapter analyses perceptions as processes. Looking at olfaction as a model system, it argues for the need to abandon a stimulus-centred perspective, where smells are thought of as stable percepts, computationally linked to external objects such as odorous molecules. Perception here is presented as a measure of changing signal ratios in an environment informed by expectancy effects from top-down processes.

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