scholarly journals Effects of hindbrain melanin-concentrating hormone and neuropeptide Y administration on licking for water, saccharin, and sucrose solutions

2008 ◽  
Vol 294 (2) ◽  
pp. R329-R343 ◽  
Author(s):  
John-Paul Baird ◽  
Catalina Rios ◽  
Jasmine L. Loveland ◽  
Janine Beck ◽  
Alice Tran ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Ingestion Rate ◽  
Third Ventricle ◽  
Meal Frequency ◽  
Testing Conditions ◽  
The Third ◽  
Sucrose Solutions ◽  
Melanin Concentrating Hormone ◽  
The Brain ◽  
Early Phases

Melanin-concentrating hormone (MCH) and neuropeptide Y (NPY) are orexigenic peptides found in hypothalamic neurons that project throughout the forebrain and hindbrain. The effects of fourth ventricle (4V) infusions of NPY (5 μg) and MCH (5 μg) on licking for water, 4 mM saccharin, and sucrose (0.1 and 1.0 M) solutions were compared to identify the contributions of each peptide to hindbrain-stimulated feeding. NPY increased mean meal size only for the sucrose solutions, suggesting that caloric feedback or taste quality is pertinent to the orexigenic effect; MCH infusions under identical testing conditions failed to produce increases for any tastant. A second experiment also observed no intake or licking effects after MCH doses up to 15 μg, supporting the conclusion that MCH-induced orexigenic responses require forebrain stimulation. A third experiment compared the 4V NPY results with those obtained after NPY infusions (5 μg) into the third ventricle (3V). In contrast to the effects observed after the 3V NPY injections and previously reported forebrain intracerebroventricular (ICV) NPY infusion studies, 4V NPY failed to increase meal frequency for any taste solution or ingestion rate in the early phases of the sucrose meals. Overall, 4V NPY responses were limited to intrameal behavioral processes, whereas forebrain ICV NPY stimulation elicited both consummatory and appetitive responses. The dissociation between MCH and NPY effects observed for 4V injections is consistent with reports that forebrain ICV injections of MCH and NPY produced nearly dichotomous effects on the pattern of licking microstructure, and, collectively, the results indicate that the two peptides have separate sites of feeding action in the brain.

Effects of melanin-concentrating hormone on licking microstructure and brief-access taste responses

2006 ◽  
Vol 291 (5) ◽  
pp. R1265-R1274 ◽  
Author(s):  
John-Paul Baird ◽  
Catalina Rios ◽  
Nora Elizabeth Gray ◽  
Caroline Elizabeth Walsh ◽  
Shannon Glenora Fischer ◽  
...  
Keyword(s):  
Third Ventricle ◽  
Taste Stimulus ◽  
Water Solutions ◽  
The Third ◽  
Sucrose Solutions ◽  
Quinine Hydrochloride ◽  
Inhibitory Feedback ◽  
Melanin Concentrating Hormone ◽  
Taste Evaluation ◽  
The Mean

The effects of intracerebroventricular application of melanin-concentrating hormone (MCH) on licking for sucrose, quinine hydrochloride (QHCl), and water solutions were evaluated in two experiments. In experiment 1, rats received 90-min access to sucrose and water solutions after MCH or vehicle microinjection to the third ventricle (3V). MCH increased intake largely through increases in the rate of licking early in the meal and in the mean duration of lick bursts, suggesting an effect on gustatory evaluation. Therefore, in experiment 2, brief access tests were used with a series of sucrose and QHCl concentrations to behaviorally isolate the effects of intracerebroventricular MCH on gustatory evaluation. MCH uniformly increased licking for all sucrose solutions, water, and weak concentrations of QHCl; however, it had no effect on licking for the strongest concentrations of QHCl, which were generally avoided under control conditions. Thus MCH did not produce nonspecific increases in oromotor activity, nor did it change the perceived intensity of the tastants. We conclude that MCH enhanced the gain of responses to normally accepted stimuli at a phase of processing after initial gustatory detection and after the decision to accept or reject the taste stimulus. A comparison of 3V NPY and MCH effects on licking microstructure indicated that these two peptides increased intake via dichotomous behavioral processes; although NPY suppressed measures associated with inhibitory feedback from the gut, MCH appeared instead to enhance measures associated with hedonic taste evaluation.

Experimental Third Ventriculostomy Performed Using Endovascular Surgical Techniques and Their Adaptation to Percutaneous Intradural Neuronavigation: Proof of Concept Cadaver Study

Neurosurgery ◽  
2003 ◽  
Vol 53 (2) ◽  
pp. 387-392 ◽  
Author(s):  
Michael B. Horowitz ◽  
Kamal Ramzipoor ◽  
Ajit Nair ◽  
Susan Miller ◽  
George Rappard ◽  
...  
Keyword(s):  
Third Ventricle ◽  
Surgical Techniques ◽  
Cadaver Study ◽  
Brain Parenchyma ◽  
Third Ventriculostomy ◽  
General Anesthetic ◽  
The Third ◽  
Noncommunicating Hydrocephalus ◽  
Pass Through ◽  
The Brain

Abstract OBJECTIVE Endoscopic third ventriculostomy has developed into a therapeutic alternative to shunting for the management of carefully selected patients with primarily noncommunicating hydrocephalus. This procedure, however, requires a general anesthetic and necessitates violation of the brain parenchyma and manipulation near vital neural structures to access the floor of the third ventricle. Using two cadavers and off-the-shelf angiographic catheters, we sought to determine whether it was possible to navigate a catheter, angioplasty balloon, and stent percutaneously through the subarachnoid space from the thecal sac into the third ventricle so as to perform a third ventriculostomy from below. METHODS Using biplane angiography and off-the-shelf angiographic catheters along with angioplasty balloons and stents, we were able to pass a stent coaxially from the thecal sac to and across the floor of the third ventricle so as to achieve a third ventriculostomy from below. RESULTS Coaxial catheter techniques allowed for the percutaneous insertion of a stent across the floor of the third ventricle. Ventriculostomy was confirmed by injecting contrast medium into the lateral ventricle and seeing it pass through the stent and into the chiasmatic cistern. CONCLUSION We describe the performance of third ventriculostomies in two cadavers by use of the new concept of percutaneous intradural neuronavigation. This procedure may obviate the need for general anesthetic and minimize the potential for brain and vascular injury, especially if ultimately combined with magnetic resonance fluoroscopy.

General concepts of hypothalamus-pituitary anatomy

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.

scholarly journals Cilia-driven flows in the brain third ventricle

2019 ◽  
Vol 375 (1792) ◽  
pp. 20190154 ◽  
Author(s):  
Gregor Eichele ◽  
Eberhard Bodenschatz ◽  
Zuzana Ditte ◽  
Ann-Kathrin Günther ◽  
Shoba Kapoor ◽  
...  
Keyword(s):  
Third Ventricle ◽  
Biochemical Properties ◽  
Brain Parenchyma ◽  
Ventricular Wall ◽  
Brain Ventricles ◽  
Cellular Targets ◽  
Signalling Molecules ◽  
The Third ◽  
Directional Transport ◽  
The Brain

The brain ventricles are interconnected, elaborate cavities that traverse the brain. They are filled with cerebrospinal fluid (CSF) that is, to a large part, produced by the choroid plexus, a secretory epithelium that reaches into the ventricles. CSF is rich in cytokines, growth factors and extracellular vesicles that glide along the walls of ventricles, powered by bundles of motile cilia that coat the ventricular wall. We review the cellular and biochemical properties of the ventral part of the third ventricle that is surrounded by the hypothalamus. In particular, we consider the recently discovered intricate network of cilia-driven flows that characterize this ventricle and discuss the potential physiological significance of this flow for the directional transport of CSF signals to cellular targets located either within the third ventricle or in the adjacent hypothalamic brain parenchyma. Cilia-driven streams of signalling molecules offer an exciting perspective on how fluid-borne signals are dynamically transmitted in the brain. This article is part of the Theo Murphy meeting issue ‘Unity and diversity of cilia in locomotion and transport’.

scholarly journals III. Contributions to the anatomy of the central nervous system in vertebrated animals. Part I.—Ichthyopsida. Section I.—Pisces. Subsection III.—Dipnoi. On the brain of the Ceratodus forsteri

1888 ◽  
Vol 43 (258-265) ◽  
pp. 420-423
Keyword(s):  
Fourth Ventricle ◽  
Third Ventricle ◽  
Pia Mater ◽  
The Third ◽  
Lateral Ventricles ◽  
Large Size ◽  
General Arrangement ◽  
Tela Choroidea ◽  
The Central Nervous System ◽  
The Brain

The brain of Ceratodus has the following general arrangement:—The membrane which represents the pia mater is of great thickness and toughness; there are two regions where a tela choroidea is developed: one where it covers in the fourth ventricle, and the other where it penetrates through the third ventricle and separates the lateral ventricles from each other. The ventricles are all of large size, and the walls of the lateral ventricles are not completed by nervous tissue. The thalamence-phalon and the mesencephalon are narrow, and the medulla oblongata is wide.

Organization of the Vascular Supply to the Brain of the Toad Bufo-Marinus

1990 ◽  
Vol 38 (4) ◽  
pp. 375
Author(s):  
GK Snyder ◽  
B Gannon ◽  
RV Baudinette
Keyword(s):  
Fourth Ventricle ◽  
Third Ventricle ◽  
Vascular Supply ◽  
Bufo Marinus ◽  
Cane Toad ◽  
The Third ◽  
Toad Bufo ◽  
The Brain ◽  
Caudal Rami ◽  
Vascular Corrosion Casts

The vasculature of the brain of the cane toad, Bufo marinus, was studied by means of scanning electron microscopy of vascular corrosion casts. The sole arterial supply to the brain is from branches of the internal carotids. The forebrain is supplied by several branches from the rostra1 ramus of the carotids; the caudal ramus gives rise to a single branch which supplies the mesencephalon and cerebellum. The caudal rami fuse to form a single basilar artery which supplies the medulla. The vascular supply to the choroid plexus of the third ventricle is arterial; the vascular supply to the choroid of the fourth ventricle is entirely venous. Microvascular geometry in the toad brain is specific to the region of the brain examined, ranging from simple long capillaries with few anastomotic connections to much shorter, highly convoluted capillaries with many anastomotic connections.

scholarly journals STUDIES IN THE PATHOGENESIS OF EXPERIMENTAL DYSENTERY INTOXICATION

1960 ◽  
Vol 111 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Abraham Penner ◽  
Alice Ida Bernheim
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Intravenous Administration ◽  
Shiga Toxin ◽  
Third Ventricle ◽  
Dosage Level ◽  
Ventricular System ◽  
The Third ◽  
The Central Nervous System ◽  
The Brain

The introduction of Shiga toxin into the ventricular system of the brain with major location in the third ventricle resulted in a response similar to that following the administration of the toxin either intravenously or by cross-circulation. The intravenous administration at the dosage level employed would have elicited no response. These observations lend support to the hypothesis that Shiga toxin activates some mechanisms in the central nervous system which are capable of producing visceral lesions. These mechanisms are those which control the vasomotor components of homeostasis. This hypothesis permits an explanation of the proximo-distal and intramural features of the lesion.

Hypothalamic Hamartoma in a Dog

1977 ◽  
Vol 14 (2) ◽  
pp. 138-145 ◽  
Author(s):  
R. W. Cook
Keyword(s):  
Cerebrospinal Fluid ◽  
Third Ventricle ◽  
Fluid Pressure ◽  
Hypothalamic Hamartoma ◽  
Tuber Cinereum ◽  
Mammillary Bodies ◽  
Spongiform Change ◽  
The Third ◽  
The Brain ◽  
Rostral Part

A 10-month-old female, Wire-haired Pointing Griffon dog had a hamartoma of the hypothalamus. Episodes of sudden flaccid collapse had increased in frequency and duration for 7 months. Cerebrospinal fluid pressure was normal. A flat, pedunculated mass, 2.5×3.0×0.9 cm, covered the brain stem between the pituitary gland and pons. Its 1.2-cm-diameter connection to the hypothalamus obliterated the mammillary bodies and extended to the tuber cinereum, distorting the hypothalamus and displacing the third ventricle which also divided the rostral part of the mass. The tissue of the hamartoma resembled gray matter with bullous cytoplasmic vacuolation of many neurons, spongiform change, gemistocytosis and microscopic foci of calcification.

Sign in / Sign up

Export Citation Format

Share Document