The paraventricular nucleus (PVN) is an aggregation of neurons in the hypothalamus, adjacent to the third ventricle. Although it is in the periventricular zone, it is not to be confused with the periventricular nucleus (PV) located nearby. The PVN is highly vascularised, but is inside the blood-brain barrier, although the neuroendocrine neurons in this nucleus project to sites (the median eminence and the posterior pituitary) that lack a blood-brain barrier. The PVN contains magnocellular neurosecretory cells whose axons extend into the posterior pituitary, parvocellular neurosecretory cells that project to the median eminence, and several populations of peptide-containing cells that project to many different brain regions. In the anatomy of mammals, the hypothalamus is a region of the brain located below the thalamus, forming the major portion of the ventral region of the diencephalon and functioning to regulate certain metabolic processes and other autonomic activities. ... The blood-brain barrier (BBB) is a membrane that controls the passage of substances from the blood into the central nervous system. ... Neuroendocrinology is the study of the interactions between the nervous system and the endocrine system. ... Median Eminence The median eminence is part of the inferior boundary for the hypothalamus. ... The posterior pituitary (also called the neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system. ... Magnocellular neurosecretory cells are cells within the supraoptic nucleus and paraventricular nucleus. ... The posterior pituitary (also called the neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ...

Magnocellular neurosecretory neurons in the PVN

The magnocellular cells in the PVN produce oxytocin and vasopressin. These peptide hormones are packaged in large dense-core vesicles, which are transported down the axons and released from neurosecretory nerve terminals in the posterior pituitary gland. Similar magnocellular neurons are found in the supraoptic nucleus. Oxytocin is a hormone, found in mammals, which in humans is released mainly after stimulation of the nipples or distention of the vagina and which facilitates birth and breastfeeding. ... Arginine vasopressin (AVP), also known as argipressin or antidiuretic hormone (ADH), is a human hormone that is mainly released when the body is low on water; it causes the kidneys to conserve water by concentrating the urine and reducing urine volume. ... Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ... An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... The posterior pituitary (also called the neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system. ... In biology, the supraoptic nucleus is a nucleus of magnocellular neurosecretory cells in the hypothalamus, their axons extend into posterior pituitary. ...

Parvocellular neurosecretory neurons

The parvocellular neurosecretory neurons of the PVN project axons to the median eminence, at the base of the brain. At the median eminence, the neurosecretory nerve terminals release peptides into the blood vessels of the hypothalamo-pituitary portal system. These vessels carry the peptides to the anterior pituitary gland, where they regulate hormone secretion into the systemic circulation. The parvocellular neurosecretory cells include: The anterior pituitary (also called the adenohypophysis) comprises the anterior lobe of the pituitary gland and is part of the endocrine system. ...

• cells that make CRH, which regulates ACTH secretion from the anterior pituitary gland,
• cells that make vasopressin: vasopressin released from these neurons also regulates ACTH secretion; vasopressin and CRF act synergistically to stimulate ACTH secretion.
• cells that make TRH, which regulates TSH secretion.

CRH can refer to: 1. ... Adrenocorticotropic hormone (ACTH or corticotropin) is a polypeptide hormone secreted from corticotropes in the anterior lobe of the pituitary gland in response to corticotropin-releasing hormone (CRH) released by the hypothalamus. ... The anterior pituitary (also called the adenohypophysis) comprises the anterior lobe of the pituitary gland and is part of the endocrine system. ... Arginine vasopressin (AVP), also known as argipressin or antidiuretic hormone (ADH), is a human hormone that is mainly released when the body is low on water; it causes the kidneys to conserve water by concentrating the urine and reducing urine volume. ... The acronym TRH usually refers to the thyrotropin-releasing hormone, but in the context of manners of address, it can refer to the following: Their Royal Highnesses, when referring to a group of royals in the British Commonwealth It may also be used to incorrectly refer to the style The... Thyroid-stimulating hormone (also known as TSH or thyrotropin) is a hormone produced by thyrotrope cells in the anterior pituitary gland which regulates the endocrine function of the thyroid gland. ...

Centrally-projecting neurons

As well as neuroendocrine neurons, the PVN contains interneurons and populations of neurons that project centrally (i.e. to other brain regions). The centrally-projecting neurons include:

• parvocellular oxtocin cells that project mainly to the brainstem and spinal cord. The oxytocin cells that project to the brainstem are involved in gastric reflexes, those that project to the spinal cord are involved in penile erection.
• parvocellular vasopressin cells that project to many areas of the hypothalamus and limbic system, as well as to the brainstem and spinal cord. These neurons are involved in blood pressure regulation and thermoregulation.
• parvocellular CRH neurons that are thought to be involved in stress-associated behaviors

The brain stem is the stalk of the brain below the cerebral hemispheres. ... Cross-section through cervical spinal cord. ... The limbic system within the brain. ...

Afferent inputs to the PVN

The PVN receives afferent inputs from many brain regions. Amongst these, inputs from neurons in structures adjacent to the anterior wall of the third ventricle ("AV3V region") carry information about the electrolyte composition of the blood, and about circulating concentrations of hormones such as angiotensin and relaxin to regulate the magnocellular neurons. Inputs from the brainstem nucleus of the solitary tract and the ventrolateral medulla carry information from the heart and stomach. Inputs from the hippocampus to the CRF neurones are important regulators of stress responses. Inputs from neuropeptide Y-containing neurons in the arcuate nucleus co-ordinate metabolic regulation via TRH secretion with regulation of energy intake. Angiotensinogen, angiotensin I (CAS# 9041-90-1) and angiotensin II (CAS# 11128-99-7) are peptides involved in maintenance of blood volume and pressure. ... Categories: Possible copyright violations ... The solitary nucleus and tract are structures in the brainstem. ... In anatomy, the stomach (in ancient Greek στόμαχος) is an organ in the gastrointestinal tract used to digest food. ... The location of the hippocampus in the human brain. ... Neuropeptide Y (NPY) is a 36 amino acid peptide neurotransmitter found in the brain and autonomic nervous system. ... The arcuate nucleus is an aggregation of neurons in the mediobasal hypothalamus, adjacent to the third ventricle and the median eminence. ...

External links

• Diagram of location in brain