8-OH-DPAT-sensitive neurons in the nucleus raphe magnus modulate thermoregulatory output in rats

Berner, Nancy J.; Grahn, Dennis A.; Heller, H. Craig

doi:10.1016/s0006-8993(99)01426-2

Cited by 48 publications

(33 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Relative high concentrations of 8-OH-DPAT were used in the dialysate in the present study compared with those used in dialysis experiments in the dorsal raphé (71). They are otherwise consistent with those used in our laboratory's previous experiments (17,34,50) and those done by other investigators in the caudal brain stem (7). Higher concentrations in the dialysate may be necessary for several reasons.…”

Section: Methodssupporting

confidence: 86%

“…A role for medullary raphé neurons in modulating shivering is also suggested by recent evidence that the activity of fusimotor fibers innervating skeletal muscle during skin cooling can be attenuated by the microinjection of glycine into the medullary raphé (87). In another report, microinjection of 8-OH-DPAT or lidocaine into the raphé magnus attenuated shivering activity during cooling in conscious rats (7).…”

mentioning

confidence: 80%

See 1 more Smart Citation

Activation of 5-HT_1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Brown¹,

Sirlin²,

Benoit³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

Activation of 5-HT 1A receptors in the medullary raphé decreases sympathetically mediated brown adipose tissue (BAT) thermogenesis and peripheral vasoconstriction when previously activated with leptin, LPS, prostaglandins, or cooling. It is not known whether shivering is also modulated by medullary raphé 5-HT 1A receptors. We previously showed in conscious piglets that activation of 5-HT 1A receptors with (Ϯ)-8-hydroxy-2-(dipropylamino)-tetralin (8-OH-DPAT) in the paragigantocellularis lateralis (PGCL), a medullary region lateral to the raphé that contains substantial numbers of 5-HT neurons, eliminates rapid eye movement (REM) sleep and decreases shivering in a cold environment, but does not attenuate peripheral vasoconstriction. Hoffman JM, Brown JW, Sirlin EA, Benoit AM, Gill WH, Harris MB, Darnall RA. Am J Physiol Regul Integr Comp Physiol 293: R518 -R527, 2007. We hypothesized that, during cooling, activation of 5-HT 1A receptors in the medullary raphé would also eliminate REM sleep and, in contrast to activation of 5-HT 1A receptors in the PGCL, would attenuate both shivering and peripheral vasoconstriction. In a continuously cool environment, dialysis of 8-OH-DPAT into the medullary raphé resulted in alternating brief periods of non-REM sleep and wakefulness and eliminated REM sleep, as observed when 8-OH-DPAT is dialyzed into the PGCL. Moreover, both shivering and peripheral vasoconstriction were significantly attenuated after 8-OH-DPAT dialysis into the medullary raphé. The effects of 8-OH-DPAT were prevented after dialysis of the selective 5-HT 1A receptor antagonist WAY-100635. We conclude that, during cooling, exogenous activation of 5-HT 1A receptors in the medullary raphé decreases both shivering and peripheral vasoconstriction. Our data are consistent with the hypothesis that neurons expressing 5-HT 1A receptors in the medullary raphé facilitate spinal motor circuits involved in shivering, as well as sympathetic stimulation of other thermoregulatory effector mechanisms. thermoregulation; serotonin; brain stem; raphé; the sudden infant death syndrome MANY NEURONS IN THE MEDULLARY raphé, including serotonergic (5-HT) neurons, project to the intermediolateral cell column (IML) of the spinal cord and modulate sympathetic outflow to thermoregulatory effector mechanisms, including brown adipose tissue (BAT) thermogenesis, vasoconstriction of thermoregulatory cutaneous vascular beds, and heart rate (HR) (14,53,58,86,89). Studies in anesthetized and conscious animals have shown that activation of 5-HT 1A receptors in the medullary raphé with the selective agonist, (Ϯ)-8-hydroxy-2-(dipropylamino)-tetralin (8-OH-DPAT), attenuates sympathetic outflow to BAT and peripheral vessels when previously elevated by LPS, leptin, or cooling (11,52,59,63,64).There is mounting evidence that medullary raphé 5-HT neurons modulate sympathetically mediated thermoregulatory mechanisms; however, little is known about the role of medullary raphé 5-HT neurons in shivering thermogenesis. Shivering is an involuntary tremor that i...

show abstract

Section: Methodssupporting

confidence: 86%

mentioning

confidence: 80%

Activation of 5-HT_1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Brown¹,

Sirlin²,

Benoit³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

show abstract

“…Keeping in mind that the estimated tissue concentration is ϳ 1 ⁄10 of the dialysate concentration (De Lange et al, 1995), 10 mM 8-OH-DPAT (estimated 1 mM tissue concentration) produced some effects on sleep, but 30 mM was necessary to obtain consistent results. These doses are consistent with those used by other investigators in the caudal brainstem (Berner et al, 1999), and larger doses may be necessary for a number of reasons. Compared with dorsal raphé 5-HT neurons, caudal medullary 5-HT neurons have faster firing rates (Heym et al, 1982b), may have fewer 5-HT 1A autoreceptors (Trulson and Frederickson, 1987), and appear to be less sensitive to 5-HT 1A agonists (Heym et al, 1982a).…”

Section: -Oh-dpat Dosessupporting

confidence: 86%

“…Nonspecific neuronal inhibition with GABA A agonists Darnall et al, 2001;Messier et al, 2002) or lidocaine (Berner et al, 1999) in this region decreases the amount of sleep and increases wakefulness. In studies focusing on the role of 5-HT neurons in the midline raphé and immediate adjacent areas, dialysis or microinjection of 8-OH-DPAT decreases sleep and increases wakefulness (Berner et al, 1999;Messier et al, 2004). We report the novel finding that 5-HT neurons in the juxtafacial PGCL play a role in the modulation of sleep and in particular, REM sleep.…”

Section: Discussionmentioning

confidence: 97%

Inhibition of Serotonergic Neurons in the Nucleus Paragigantocellularis Lateralis Fragments Sleep and Decreases Rapid Eye Movement Sleep in the Piglet: Implications for Sudden Infant Death Syndrome

Darnall¹,

Harris²,

Gill³

et al. 2005

J. Neurosci.

View full text Add to dashboard Cite

Serotonergic receptor binding is altered in the medullary serotonergic nuclei, including the paragigantocellularis lateralis (PGCL), in many infants who die of sudden infant death syndrome (SIDS). The PGCL receives inputs from many sites in the caudal brainstem and projects to the spinal cord and to more rostral areas important for arousal and vigilance. We have shown previously that local unilateral nonspecific neuronal inhibition in this region with GABA A agonists disrupts sleep architecture. We hypothesized that specifically inhibiting serotonergic activity in the PGCL would result in less sleep and heightened vigilance. We analyzed sleep before and after unilaterally dialyzing the 5-HT 1A agonist (

show abstract

“…Serotonin facilitates preganglionic sympathetic neurons (Lewis and Coote, 1990;Pickering et al, 1994). Reducing serotonergic cell discharge increases the tail temperature of rats during ambient cold, thereby increasing heat loss (Berner et al, 1999), and inhibits the activation of BAT after intracerebroventricular injections of leptin (Morrison, 2004b). Importantly, our data provide the additional stringency of individual cell recordings concurrent with records of the appropriate physiological measure, BAT temperature.…”

Section: Discussion P5ht Cells and Cold Defensementioning

confidence: 73%

Medullary Raphe Neurons Facilitate Brown Adipose Tissue Activation

Nason¹,

Mason²

2006

J. Neurosci.

View full text Add to dashboard Cite

Recent evidence suggests that neurons in the medullary raphe are critical to the activation of brown adipose tissue (BAT), the major source of nonshivering heat production in the rat. Yet it is unclear which medullary raphe cells participate in cold defense and how participating cells contribute to BAT activation. Therefore, we recorded extracellularly from raphe cells during three thermoregulatory challenges that evoked an increase in BAT temperature in anesthetized rats: central cold, ambient cold, or intracerebroventricular prostaglandin E 2 (PGE 2 ) injection. Physiologically identified serotonergic (p5HT) cell discharge increased in response to cold or PGE

show abstract

8-OH-DPAT-sensitive neurons in the nucleus raphe magnus modulate thermoregulatory output in rats

Cited by 48 publications

References 23 publications

Activation of 5-HT_1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Activation of 5-HT_1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Inhibition of Serotonergic Neurons in the Nucleus Paragigantocellularis Lateralis Fragments Sleep and Decreases Rapid Eye Movement Sleep in the Piglet: Implications for Sudden Infant Death Syndrome

Medullary Raphe Neurons Facilitate Brown Adipose Tissue Activation

Contact Info

Product

Resources

About

8-OH-DPAT-sensitive neurons in the nucleus raphe magnus modulate thermoregulatory output in rats

Cited by 48 publications

References 23 publications

Activation of 5-HT1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Activation of 5-HT1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Inhibition of Serotonergic Neurons in the Nucleus Paragigantocellularis Lateralis Fragments Sleep and Decreases Rapid Eye Movement Sleep in the Piglet: Implications for Sudden Infant Death Syndrome

Medullary Raphe Neurons Facilitate Brown Adipose Tissue Activation

Contact Info

Product

Resources

About

Activation of 5-HT_1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet

Activation of 5-HT_1Areceptors in medullary raphé disrupts sleep and decreases shivering during cooling in the conscious piglet