- Title
- Blockade of the dorsomedial hypothalamus and the perifornical area inhibits respiratory responses to arousing and stressful stimuli
- Creator
- Bondarenko, Evgeny; Beig, Mirza I.; Hodgson, Deborah M.; Braga, Valdir A.; Nalivaiko, Eugene
- Relation
- AJP: Regulatory, Integrative and Comparative Physiology Vol. 308, Issue 10, p. R816-R822
- Publisher Link
- http://dx.doi.org/10.1152/ajpregu.00415.2014
- Publisher
- American Physiological Society
- Resource Type
- journal article
- Date
- 2015
- Description
- The dorsomedial hypothalamus (DMH) and the perifornical area (DMH/PeF) is one of the key regions of central autonomic processing. Previous studies have established that this region contains neurons that may be involved in respiratory processing; however, this has never been tested in conscious animals. The aim of our study was to investigate the involvement of the DMH/PeF area in mediating respiratory responses to stressors of various intensities and duration. Adult male Wistar rats (n = 8) received microinjections of GABAA agonist muscimol or saline into the DMH/PeF bilaterally and were subjected to a respiratory recording using whole body plethysmography. Presentation of acoustic stimuli (500-ms white noise) evoked transient responses in respiratory rate, proportional to the stimulus intensity, ranging from +44 ± 27 to +329 ± 31 cycles/min (cpm). Blockade of the DMH/PeF almost completely abolished respiratory rate and tidal volume responses to the 40- to 70-dB stimuli and also significantly attenuated responses to the 80- to 90-dB stimuli. Also, it significantly attenuated respiratory rate during the acclimatization period (novel environment stress). The light stimulus (30-s 2,000 lux) as well as 15-min restraint stress significantly elevated respiratory rate from 95 ± 4.0 to 236 ± 29 cpm and from 117 ± 5.2 to 189 ± 13 cpm, respectively; this response was abolished after the DMH/PeF blockade. We conclude that integrity of the DMH/PeF area is essential for generation of respiratory responses to both stressful and alerting stimuli.
- Subject
- dorsomedial hypothalamus; respiratory rate; tidal volume; arousal; stress
- Identifier
- http://hdl.handle.net/1959.13/1336785
- Identifier
- uon:27703
- Identifier
- ISSN:1522-1490
- Language
- eng
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