5-hydroxytryptamine2A receptors regulate sympathetic nerves constricting the cutaneous vascular bed in rabbits and rats

Blessing, W.W.; Seaman, B

doi:10.1016/s0306-4522(02)00810-2

Cited by 75 publications

(54 citation statements)

References 49 publications

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“…Taken together with our demonstration in a previous study (8) that the vigorous ear pinnavasoconstricting effect of DOI is entirely prevented by section of the cervical sympathetic trunk, the present findings provide strong evidence that raphé-spinal excitation of cutaneous vasomotor sympathetic preganglionic neurons is partially dependent on excitation of 5-HT 2A receptors in the region of the spinal cord containing the relevant sympathetic preganglionic neurons.…”

Section: Axonal Conduction Velocity Of Raphé-spinal Neurons Activatinsupporting

confidence: 88%

Activation of slowly conducting medullary raphé-spinal neurons, including serotonergic neurons, increases cutaneous sympathetic vasomotor discharge in rabbit

Ootsuka¹,

Blessing²

2005

American Journal of Physiology-Regulatory, Integrative and Comp

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Ootsuka, Youichirou, and William W. Blessing. Activation of slowly conducting medullary raphé-spinal neurons, including serotonergic neurons, increases cutaneous sympathetic vasomotor discharge in rabbit. Am J Physiol Regul Integr Comp Physiol 288: R909 -R918, 2005. First published November 18, 2004; doi:10.1152/ajpregu.00564. 2004.-Neurons in the rostral medullary raphé/parapyramidal region regulate cutaneous sympathetic nerve discharge. Using focal electrical stimulation at different dorsoventral raphé/parapyramidal sites in anesthetized rabbits, we have now demonstrated that increases in ear pinna cutaneous sympathetic nerve discharge can be elicited only from sites within 1 mm of the ventral surface of the medulla. By comparing the latency to sympathetic discharge following stimulation at the ventral raphé site with the corresponding latency following stimulation of the spinal cord [third thoracic (T3) dorsolateral funiculus] we determined that the axonal conduction velocity of raphé-spinal neurons exciting ear pinna sympathetic vasomotor nerves is 0.8 Ϯ 0.1 m/s (n ϭ 6, range 0.6 -1.1 m/s). Applications of the 5-hydroxytryptamine (, 80 g/kg in 0.8 ml) to the cerebrospinal fluid above thoracic spinal cord (T1-T7), but not the lumbar spinal cord (L2-L4), reduced raphé-evoked increases in ear pinna sympathetic vasomotor discharge from 43 Ϯ 9 to 16 Ϯ 6% (P Ͻ 0.01, n ϭ 8). Subsequent application of the excitatory amino acid (EAA) antagonist kynurenic acid (25 mol in 0.5 ml) substantially reduced the remaining evoked discharge (22 Ϯ 8 to 6 Ϯ 6%, P Ͻ 0.05, n ϭ 5). Our conduction velocity data demonstrate that only slowly conducting raphé-spinal axons, in the unmyelinated range, contribute to sympathetic cutaneous vasomotor discharge evoked by electrical stimulation of the medullary raphé/parapyramidal region. Our pharmacological data provide evidence that raphé-spinal neurons using 5-HT as a neurotransmitter contribute to excitation of sympathetic preganglionic neurons regulating cutaneous vasomotor discharge. Raphé-spinal neurons using an EAA, perhaps glutamate, make a substantial contribution to the ear sympathetic nerve discharge evoked by raphé stimulation.5-hydroxytryptamine2A receptors; kynurenic acid; SR-46349B; sympathetic preganglionic neuron; cutaneous blood flow NEURONS IN THE ROSTRAL MEDULLARY raphé/parapyramidal region regulate cutaneous vasomotor tone by controlling cutaneous sympathetic preganglionic neuronal activity (7,39,42,45). Identification and characterization of the relevant neurons is an important task. Activity of these neurons contributes to the heat exchange aspect of thermoregulation as well as to the integrated bodily response to nociceptive or salient environmental events (7,21,35,36,39,42,45,49). Neuroanatomic studies using transneuronal transport of live virus injected into the tail vasculature indicate that a proportion of sympathetic premotor raphé-spinal neurons synthesize serotonin (5-hydroxytryptamine, 5-HT) (32, 44).Although 5-HT is a neurotransmitter traditionally considered...

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Section: Axonal Conduction Velocity Of Raphé-spinal Neurons Activatinsupporting

confidence: 88%

Activation of slowly conducting medullary raphé-spinal neurons, including serotonergic neurons, increases cutaneous sympathetic vasomotor discharge in rabbit

Ootsuka¹,

Blessing²

2005

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Intravenous administration of a 5-HT 2A -receptor agonist facilitates the cutaneous sympathetic outflow (Blessing and Seaman, 2003), potentially at the IML site of sympathetic preganglionic neurons (Ootsuka and Blessing, 2005), and thus could contribute to an elevated arterial pressure in response to central 5-HT 2A -receptor agonist administration.…”

Section: -Ht and Blood Pressurementioning

confidence: 99%

Serotonin and Blood Pressure Regulation

et al. 2012

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“…As far as cardiovascular changes are concerned, stress may induce both modifications in heart rate and heart rate variability (HRV), as well as vascular changes in different body's parts, including the skin (Blessing, 2003;Walker and Carrive, 2003). Similar physiological reactions have been shown stimuli in the rat's tail and in the rabbit's ear in response to alerting (Blessing and Seaman, 2003;Yu and Blessing, 2001). Emotional arousal during wakefulness may affect body temperature.…”

Section: Introductionmentioning

confidence: 99%

“…Complex regulatory mechanisms control body and skin temperature; these involve 'stimulation and withdrawal of sympathetic tone to arteries, arterioles, venules, veins and arteriovenous anastomoses' (Pollock et al, 1994). Moreover, the cutaneous vasoconstriction contributes to the hyperthermia (Blessing and Seaman, 2003) in the body. Thus skin blood flow and sympathetic vasoconstrictor outflow to skin arteries affect skin temperature (Vianna and Carrive, 2005).…”

Section: Introductionmentioning

confidence: 99%

Technical note: Applicability of infrared thermography as a non invasive measurements of stress in rabbit.

Ludwig¹,

Gargano²,

Luzi³

et al. 2010

World rabbit sci.

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Among the main physiological stress indicators, the temperature evaluation is very important and innovative because it may be monitored without directly interacting with the animal. The use of a thermographic system, which is based on the detection of infrared radiation emitted by a subject, is a suitable method in order to measure temperature without any contact. In this research, a thermographic system was employed in order to single out the rabbit skin's zones most suitable for the temperature monitoring during stress challenges. Six hybrid rabbits were observed during induced stress; the areas selected as reference were: the ocular area (globe and periocular area), the internal auricle pavilion, and a shaved area of the head. The results of this pilot study show that the thermographic technique is a suitable method for the evaluation of temperature on rabbit. The best areas singled out were the eye bulb, the periocular area and the ear skin. The results concerning the effect of stress on cutaneous temperature showed that during stress condition a decrease in temperature occurs with respect to the basal condition (ΔT~1°C) and this trend is more evident for the auricle pavillion. In fact, this reaction is more evidenced in the ear skin, where a vasoconstriction process occurs. Moreover, corticosterone levels slightly increase (P=0.08) following the stressor's challenge due to tonic immobility test. In this research, both temperature and the change in corticosterone level show that the stress reaction induced by tonic immobility test is stronger than the one due to the other stressors applied to rabbits.

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5-hydroxytryptamine2A receptors regulate sympathetic nerves constricting the cutaneous vascular bed in rabbits and rats

Cited by 75 publications

References 49 publications

Activation of slowly conducting medullary raphé-spinal neurons, including serotonergic neurons, increases cutaneous sympathetic vasomotor discharge in rabbit

Activation of slowly conducting medullary raphé-spinal neurons, including serotonergic neurons, increases cutaneous sympathetic vasomotor discharge in rabbit

Serotonin and Blood Pressure Regulation

Technical note: Applicability of infrared thermography as a non invasive measurements of stress in rabbit.

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