Autism, Downs,autonomic, neuroimmune, VIP, CGRP,etc.

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1- Reduced cardiac parasympathetic activity in children with autism

2-Baroreflex sensitivity during static exercise in individuals with Down

Syndrome.

3-Neural-immune interactions: An integrative view of the bidirectional

relationship between the brain and immune systems.

4-Cardioprotective role of the VIP signaling system.

5-Neurobiology in primary headaches.

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Brain Dev. 2005 Oct;27(7):509-16.

Reduced cardiac parasympathetic activity in children with autism.

Ming X, Julu PO, Brimacombe M, Connor S, s ML.

Department of Neuroscience, New Jersey Medical School, UMDNJ, Newark, 90

Bergen Street, DOC 8100, NJ 07103, USA. mingxu@...

Many of the clinical symptoms of autism suggest autonomic dysfunction. The

aim of this study was to measure baseline cardiovascular autonomic function

in children with autism using the NeuroScope, a device that can measure this

brainstem function in real-time. Resting cardiac vagal tone (CVT), cardiac

sensitivity to baroreflex (CSB), mean arterial blood pressure (MAP),

diastolic blood pressure (DBP), systolic blood pressure (SBP) and heart rate

(HR) were recorded in three different groups of children. The symptomatic

group (n = 15) consisted of those with autism who exhibited symptoms or

signs of autonomic dysfunction. The asymptomatic group (n = 13) consisted of

children with autism but without symptoms or signs of autonomic dysfunction

and the healthy children were in the control group (n = 117).

The CVT and CSB were significantly lower in association with a significant

elevation in HR, MAP and DBP in all children with autism compared with the

healthy controls. Further more, the levels of CVT and CSB were lower in the

symptomatic than in the asymptomatic group. The levels of CVT and CSB were

not related to age in all the three groups.

These results suggest that there is low baseline cardiac parasympathetic

activity with evidence of elevated sympathetic tone in children with autism

whether or not they have symptoms or signs of autonomic abnormalities.

PMID: 16198209 [PubMed - indexed for MEDLINE]

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Med Sci Sports Exerc. 2005 Dec;37(12):2026-31.

Baroreflex sensitivity during static exercise in individuals with Down

Syndrome.

Heffernan KS, Baynard T, Goulopoulou S, Giannopoulou I, Collier SR, Figueroa

A, Fernhall B.

Department of Kinesiology and Community Health University of Illinois at

Urbana Champaign Champaign, IL 61820, USA.

INTRODUCTION: Individuals with Down syndrome (DS) have altered heart rate

(HR) and blood pressure (BP) responses to orthostatic challenges and

isometric handgrip (IHG) exercise, suggesting possible alteration in

baroreflex sensitivity.

PURPOSE: This study investigated baroreflex sensitivity (BRS) as a potential

mechanism contributing to chronotropic incompetence during IHG in persons

with DS. METHODS: Heart rate and BP were continually recorded in 12

individuals with DS and 10 controls, at rest and during 2 min of IHG, at 30%

of maximal voluntary contraction (MVC). Spontaneous BRS was derived via the

sequence method.

RESULTS: No differences were seen in HR at rest between groups. Systolic BP

(SBP) was significantly lower in the DS group at rest (106.1+/- 2.9 vs

116.5+/- 3.9 mm Hg, P < 0.05) and during IHG (123.9+/- 4.6 vs 150.1+/- 5.3

mm Hg, P<0.001).

A significant group-by-task interaction was found for both change in HR and

change in SBP with IHG, because of an attenuated HR and SBP response to IHG

in participants with DS (P<0.05). When controlling for resting SBP, the DS

group had a lower BRS at rest (16.0+/-1.7 vs 21.2+/-4.2 ms.mm Hg, P< 0.05)

and during IHG (7.8 +/-1.0 vs 12.1+/- 2.6 ms.mm Hg, P< 0.05).

CONCLUSIONS: Individuals with DS have lower BRS at rest and during IHG than

controls and this may be related to their attenuated HR response during

perturbation.

PMID: 16331125 [PubMed - in process]

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J Neuroimmunol. 2005 Dec 20; [Epub ahead of print]

Neural-immune interactions: An integrative view of the bidirectional

relationship between the brain and immune systems.

Wrona D.

Department of Animal Physiology, University of Gdansk, Poland.

This review briefly summarizes a part of the relevant knowledge base of

neuroimmunology, with particular emphasis on bidirectional neural-immune

interactions. These complex systems interact at multiple levels.

Both neuroendocrine (the primary hormonal pathway is

hypothalamic-pituitary-adrenal axis) and neuronal (direct sympathetic

innervation of the lymphoid organs) pathways are involved in the control of

the humoral and cellular immune responses.

Although, the recent evidence has been made on immunosuppressive effect of

acetylcholine-secreting neurons of the parasympathetic nervous system.

The immune system, in turn, influences the central nervous system primarily

through cytokines.

At the molecular level, neuro- and immune signal molecules (hormones,

neurotransmitters, neuropeptides, cytokines) or their receptors are member

of the same superfamily which enable the mutual neuroimmune communication.

Most extensively studied are cytokine-neuropeptide/neurotransmitter

interactions and the subcellular and molecular mechanisms of these

interactions. At the system (neuroanatomical) level, advances in

neural-immune communication have been made in the role of discrete brain

areas related to emotionality. The immunoenhancement, including the

antiviral and antitumor cytotoxic activity, related to the " brain reward

system " , limbic structures and neocortex, offers a new directions for

therapy in immune disorders.

PMID: 16375977 [PubMed - as supplied by publisher]

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Timely Top Med Cardiovasc Dis. 2005 Oct 3;9:E33.

Cardioprotective role of the VIP signaling system.

Dvorakova MC.

Department of Physiology, Faculty of Medicine, University, Plzeo,

Czech Republic. magdalena.dvorakova@....

Vasoactive intestinal peptide (VIP) is a 28-amino acid peptide that belongs

to a family of structurally related peptide hormones including pituitary

adenylate cyclase-activating peptide (PACAP). These hormones are widely

distributed in the nervous system, where they act as neurotransmitters.

Their biological effects are mediated by specific receptors, VPAC1 and

VPAC2, which have comparable affinity for VIP and PACAP, and PAC1, which

binds VIP with 1,000-fold lower affinity than PACAP.

Both peptides are involved in autonomic regulation of the cardiovascular

system, where they exert positive inotropic and chronotropic effects, and

cause coronary vasodilatation. Additionally, PACAP inhibits proliferation of

cardiac fibroblasts. Several cardiovascular diseases, such as myocardial

fibrosis, heart failure, cardiomyopathy and pulmonary hypertension, have

been found to be associated with changes in myocardial VIP concentration or

with alteration of affinity, density and physiological responsiveness of

VIP/PACAP receptors.

Application of the peptides or their agonists has beneficial effect in

hypertension, heart failure and myocardial fibrosis.

Taken together, VIP and PACAP have beneficial effects in various

pathological conditions. © 2005 Prous Science. All rights reserved.

PMID: 16341283 [PubMed - in process]

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Brain Res Brain Res Rev. 2005 Jun;48(3):438-56. Epub 2004 Nov 18.

Neurobiology in primary headaches.

Edvinsson L, Uddman R.

Department of Internal Medicine, University Hospital, S-221 85 Lund, Sweden.

lars.edvinsson@...

Primary headaches such as migraine and cluster headache are neurovascular

disorders. Migraine is a painful, incapacitating disease that affects a

large portion of the adult population with a substantial economic burden on

society. The disorder is characterised by recurrent unilateral headaches,

usually accompanied by nausea, vomiting, photophobia and/or phonophobia. A

number of hypothesis have emerged to explain the specific causes of

migraine. Current theories suggest that the initiation of a migraine attack

involves a primary central nervous system (CNS) event. It has been suggested

that a mutation in a calcium gene channel renders the individual more

sensitive to environmental factors, resulting in a wave of cortical

spreading depression when the attack is initiated. Genetically, migraine is

a complex familial disorder in which the severity and the susceptibility of

individuals are most likely governed by several genes that vary between

families. Genom wide scans have been performed in migraine with

susceptibility regions on several chromosomes some are associated with

altered calcium channel function. With positron emission tomography (PET), a

migraine active region has been pointed out in the brainstem. In cluster

headache, PET studies have implicated a specific active locus in the

posterior hypothalamus.

Both migraine and cluster headache involve activation of the

trigeminovascular system. In support, there is a clear association between

the head pain and the release of the

neuropeptide calcitonin gene-related peptide (CGRP) from the

trigeminovascular system. In cluster headache there is, in addition, release

of the

parasympathetic neuropeptide vasoactive intestinal peptide (VIP)

that is coupled to facial vasomotor symptoms. Triptan administration,

activating the 5-HT(1B/1D) receptors, causes the headache to subside and the

levels of neuropeptides to normalise, in part through presynaptic inhibition

of the cranial sensory nerves. These data suggest a central role for sensory

and parasympathetic mechanisms in the pathophysiology of primary headaches.

The positive clinical trial with a CGRP receptor antagonist offers a new

promising way of treatment.

Publication Types:

Review

PMID: 15914251 [PubMed - indexed for MEDLINE]

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