Glutamatergic projections from the rostral hypothalamus to the periaqueductal grey

Parry, Dilys M.; Johns, Nina; Semenenko, F. M.; Snowball, R.K; Hudson, P.M; Lumb, Bridget M.

doi:10.1097/00001756-199606170-00020

Cited by 6 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The exception to the facilitatory effect of pup presence on anxiety-induced Fos expression was the mPOAd, where previous litter presence had a generally suppressive effect. The majority of cells in the mPOAd are also GABAergic [55], but some of its projection neurons to neural areas modulating anxiety and stress responses -such as the posterior hypothalamus and PAG -are not [29,35,66]. The simplest hypothesis is that these excitatory projections need to be suppressed in low-anxiety mothers, which is reflected by low c-fos activity when mothers are faced with anxiogenic stimuli.…”

Section: Fos Expression In Response To Anxiogenic Stimuli Is Modulatementioning

confidence: 99%

Contact with infants modulates anxiety-generated c-fos activity in the brains of postpartum rats

Smith

Lonstein

2008

Behavioural Brain Research

View full text Add to dashboard Cite

The postpartum period is associated with many behavioral changes, including a reduction in anxiety, which is thought to be necessary for mothers' ability to appropriately care for infants. In laboratory rats, this reduction in anxiety requires recent contact with pups, but areas of the brain where infant contact influences neural activity to reduce anxiety are mostly unknown. We examined c-fos expression in lactating rats whose pups were removed for 4h to increase mothers' anxiety, or not removed to maintain low anxiety in mothers, followed by exposure to the anxiogenic stimuli of either brief handling or handling followed by exposure to an elevated plus maze. Control animals had their litters removed or not, but no further stimulation. A large number of neural sites traditionally implicated in regulating anxiety in male rats were examined, and similar to what is found in male rats, most showed increased Fos expression after handling and/or elevated plus-maze exposure. Litter presence before testing affected Fos expression due to handling or elevated plus-maze exposure only in the ventral bed nucleus of the stria terminalis, dorsal and ventral preoptic area, ventromedial hypothalamus, lateral habenula, and supramammillary nucleus. Contrary to expectations, prior litter presence was associated with more Fos expression in most of these sites after handling and/or elevated plus-maze stimulation, and only after such stimulation. These sites may be of particular importance for how sensory inputs from infants modulate anxiety and other mood states during the postpartum period.

show abstract

Section: Fos Expression In Response To Anxiogenic Stimuli Is Modulatementioning

confidence: 99%

Contact with infants modulates anxiety-generated c-fos activity in the brains of postpartum rats

Smith

Lonstein

2008

Behavioural Brain Research

View full text Add to dashboard Cite

show abstract

“…In the cat, defence rage behaviour can be elicited from the hypothalamus. It is now well established that a pathway from the hypothalamus to the periaqueductal gray matter (PAG) mediates this form of emotional behaviour and utilizes excitatory amino acids as neurotransmitters (16, 17), which have been suggested to act on NMDA receptors in the PAG (18).…”

Section: Introductionmentioning

confidence: 99%

Effect of combined treatment with nandrolone and cocaine on the NMDA receptor gene expression in the rat nucleus accumbens and periaqueductal gray

Grevès

Zhou

Huang

et al. 2002

Acta Psychiatr Scand

View full text Add to dashboard Cite

Objective: Anabolic androgenic steroids (AAS) have been suggested to sensitize mechanisms involved in drug dependency and aggressive behaviour. Nucleus accumbens and periaqueductal gray (PAG) are believed to be critical in the functional anatomy of these two phenomena, which are partly mediated by the NMDA receptor. This study was undertaken in order to determine the relationship between the effect of AAS and cocaine (given alone or in combination) on the gene expression of the NMDA receptor subtype NR1 in the rat nucleus accumbens and PAG. Method: Male rats were subjected to 2 weeks of daily doses of cocaine and the anabolic‐androgenic steroid nandrolone, administrated separately or in combination, and the effect on the mRNA expression for the NMDA receptor NR1 subunit was studied by Northern blot analysis. Results: In the nucleus accumbens, injection of cocaine alone and the combination of cocaine and nandrolone caused a significant decrease in the NR1 mRNA level compared with that of control rats. The combined treatment significantly down‐regulated the transcript in the PAG compared with the groups injected with vehicle, nandrolone or cocaine alone. Conclusion: It was concluded that AAS combined with cocaine may induce additive increases in glutamatergic activity in these brain areas, supporting the notion that these steroids can sensitize mechanisms involved in the reward and the expression of aggression.

show abstract

“…This result is consistent with the impact of RmTBI on orexin cell bodies in animals who received RmTBIs versus those with sham injuries (outlined above). The functional losses, likely caused by DAI, on these efferent hypothalamic projections could have a chronic implication as the specific functional changes would be dependent on the different hypothalamic nuclei affected – which have unique functional and anatomical relations [ 77 ].…”

Section: Discussionmentioning

confidence: 99%

Repeat mild traumatic brain injuries (RmTBI) modify nociception and disrupt orexinergic connectivity within the descending pain pathway

Christensen,

MacPherson,

et al. 2023

J Headache Pain

View full text Add to dashboard Cite

Repeat mild traumatic brain injuries (RmTBI) result in substantial burden to the public health system given their association with chronic post-injury pathologies, such as chronic pain and post-traumatic headache. Although this may relate to dysfunctional descending pain modulation (DPM), it is uncertain what mechanisms drive changes within this pathway. One possibility is altered orexinergic system functioning, as orexin is a potent anti-nociceptive neuromodulator. Orexin is exclusively produced by the lateral hypothalamus (LH) and receives excitatory innervation from the lateral parabrachial nucleus (lPBN). Therefore, we used neuronal tract-tracing to investigate the relationship between RmTBI and connectivity between lPBN and the LH, as well as orexinergic projections to a key site within the DPM, the periaqueductal gray (PAG). Prior to injury induction, retrograde and anterograde tract-tracing surgery was performed on 70 young-adult male Sprague Dawley rats, targeting the lPBN and PAG. Rodents were then randomly assigned to receive RmTBIs or sham injuries before undergoing testing for anxiety-like behaviour and nociceptive sensitivity. Immunohistochemical analysis identified distinct and co-localized orexin and tract-tracing cell bodies and projections within the LH. The RmTBI group exhibited altered nociception and reduced anxiety as well as a loss of orexin cell bodies and a reduction of hypothalamic projections to the ventrolateral nucleus of the PAG. However, there was no significant effect of injury on neuronal connectivity between the lPBN and orexinergic cell bodies within the LH. Our identification of structural losses and the resulting physiological changes in the orexinergic system following RmTBI begins to clarify acute post-injury mechanistic changes that drive may drive the development of post-traumatic headache and the chronification of pain.

show abstract

Glutamatergic projections from the rostral hypothalamus to the periaqueductal grey

Cited by 6 publications

References 0 publications

Contact with infants modulates anxiety-generated c-fos activity in the brains of postpartum rats

Contact with infants modulates anxiety-generated c-fos activity in the brains of postpartum rats

Effect of combined treatment with nandrolone and cocaine on the NMDA receptor gene expression in the rat nucleus accumbens and periaqueductal gray

Repeat mild traumatic brain injuries (RmTBI) modify nociception and disrupt orexinergic connectivity within the descending pain pathway

Contact Info

Product

Resources

About