The sensory circumventricular organs of the mammalian brain : subfornical organ, OVLT and area postrema / M.J. McKinley ... [and others].

Format:

Book

Contributor:

McKinley, M. J. (Michael J.), 1946-

Series:

Advances in anatomy, embryology, and cell biology 0301-5556 ; v. 172.

Advances in anatomy, embryology, and cell biology 0301-5556 ; v. 172

Language:

English

Subjects (All):

Circumventricular organs.

Cerebral Ventricles.

Medical Subjects:

Cerebral Ventricles.

Physical Description:

xii, 127 pages : illustrations ; 24 cm.

Place of Publication:

Berlin ; New York : Springer-Verlag, 2003.

Summary:

The brain's three sensory circumventricular organs, the subfornical organ, organum vasculosum of the lamina terminalis and the area postrema lack a blood brain barrier and are the only regions in the brain in which neurons are exposed to the chemical environment of the systemic circulation. Therefore they are ideally placed to monitor the changes in osmotic, ionic and hormonal composition of the blood.

Contents:

2 Location, General Structure and Ependymal Cells of Sensory Circumventricular Organs 3

2.1 Subfornical Organ 3

2.1.1 Location 3

2.1.2 Ependymal Surface of the Subfornical Organ 7

2.2 OVLT 7

2.2.1 Location and Structure 7

2.2.2 Ependymal Surface of the OVLT 14

2.3 Area Postrema 15

2.3.1 Location and Structure 15

2.3.2 Ependymal Surface of the Area Postrema 16

3 Regional Subdivisions Within Sensory Circumventricular Organs 17

3.1 Subfornical Organ 17

3.2 OVLT 19

3.3 Area Postrema 21

4 Vasculature, Compartmental Barriers, Neurons and Glia in the Sensory Circumventricular Organs 23

4.1 Subfornical Organ 23

4.1.1 Arterial Sources and Venous Drainage 23

4.1.2 Capillary Plexus 23

4.1.3 Compartmental Barriers 26

4.1.4 Neurons and Glia 28

4.2 OVLT 28

4.2.1 Arterial Sources 28

4.2.2 Capillary Plexus and Venous Drainage 30

4.2.3 Compartmental Barriers 30

4.2.4 Neurons and Glia 30

4.3 Area Postrema 32

4.3.1 Arterial Sources and Venous Drainage 32

4.3.2 Capillary Plexus 32

4.3.3 Compartmental Barriers 33

4.3.4 Neurons and Glia 33

5 Neurochemical Aspects of Sensory Circumventricular Organs 35

5.1 Receptors 35

5.1.1 Acetylcholine 35

5.1.2 Angiotensin 36

5.1.3 Bradykinin 39

5.1.4 Calcium 39

5.1.5 Calcitonin, Calcitonin Gene-Related Peptide Amylin and Adrenomedullin 39

5.1.6 Cholecystokinin 41

5.1.7 Endothelin 41

5.1.8 Galanin 42

5.1.9 [gamma]-Aminobutyric acid 42

5.1.10 Glucagon-Like Peptide-1 Amide 42

5.1.11 Glutamate 43

5.1.12 Imidazoline Receptors 43

5.1.13 Lipopolysaccharide 43

5.1.14 Natriuretic Peptides (ANP, BNP and CNP) 44

5.1.15 Neurokinin Receptors 44

5.1.16 Neurotensin 44

5.1.17 Neuropeptide Y, Peptide YY, Pancreatic Polypeptide 45

5.1.18 Prostaglandins 45

5.1.19 Purinergic Receptors 45

5.1.20 Relaxin 45

5.1.21 Serotonin 46

5.1.22 Somatostatin 46

5.1.23 Steroid Receptors 46

5.1.24 Vasopressin and Oxytocin Receptors 47

5.2 Neurotransmitters, Neuropeptides, Hormones and Enzymes 47

5.2.1 Acetylcholine 47

5.2.2 Angiotensin II, Angiotensin III and Angiotensinogen 47

5.2.3 Angiotensin-Converting Enzyme 48

5.2.4 Catecholamines 48

5.2.5 Cholecystokinin 49

5.2.6 Enkephalin 49

5.2.7 Glutamate, GABA and Glycine 49

5.2.8 Luteinising Hormone-Releasing Hormone 50

5.2.9 Neurotensin 50

5.2.10 Nitric Oxide Synthase 50

5.2.11 Orexins 52

5.2.12 Proopiomelanocortin Peptides and Enkephalin 52

5.2.13 Serotonin 52

5.2.14 Vasopressin 54

6 The Neural Connections of the Sensory Circumventricular Organs 55

6.1 Subfornical Organ 55

6.1.1 Efferent Neural Connections 55

6.1.1.1 Viral Tracing 59

6.1.2 Afferent Neural Pathways of the Subfornical Organ 59

6.2 Neural Connections of the OVLT 61

6.2.1 Efferent Projections 61

6.2.1.1 Polysynaptic Efferent Pathways to the Periphery 62

6.2.2 Afferent Projections 63

6.3 Area Postrema 64

6.3.1 Efferent Neural Connections 64

6.3.2 Afferent Projections 66

7 Immediate-Early Gene Expression in Sensory Circumventricular Organs 67

7.1 Angiotensin II 67

7.1.1 Intravenous Infusion of Angiotensin II 67

7.1.2 Intracerebroventricular Angiotensin II 68

7.1.3 Endogenous Angiotensin II 69

7.1.3.1 Sodium Depletion 69

7.1.3.2 Haemorrhage 71

7.1.3.3 Isoproterenol 71

7.1.3.4 Locally Generated Angiotensin II in the CVOs 71

7.2 Baroreceptor Activation 72

7.3 Carbachol 73

7.4 Anorectic Peptides-Cholecystokinin, GLP-1 and Amylin 73

7.5 Hypertonicity 74

7.5.1 Intravenous Infusion of Hypertonic Solutions 74

7.5.2 Dehydration 76

7.6 Lipopolysaccharide (Endotoxin) 77

7.7 Relaxin 78

7.8 Vomiting and Emetic Stimuli 78

8 Functions of the Sensory Circumventricular Organs 81

8.1 Osmoregulation 81

8.1.1 Sites of Cerebral Osmoreceptors 82

8.1.2 Osmoregulation of Natriuresis and Renin Secretion 85

8.1.3 Influences of Relaxin on Osmoregulation 86

8.2 Central Actions of Circulating Angiotensin 87

8.2.1 Water Drinking 87

8.2.2 Angiotensin-Induced Vasopressin Secretion 88

8.2.3 Sodium Hunger 89

8.3 Influences on Arterial Pressure 90

8.3.1 Area Postrema 90

8.3.2 OVLT 92

8.3.3 Subfornical Organ 93

8.3.4 The Extended Autonomic Neuraxis 93

8.4 Area Postrema and Vomiting 94

8.5 Neuroimmune Responses and Fever 95.

Notes:

Includes bibliographical references and index.

ISBN:

354000419X

OCLC:

51454565