Role of hippocampal orexin receptors in antinociception elicited by chemical stimulation of the lateral hypothalamus in the tail-flick test

Adolescent ethanol drinking promotes hyperalgesia, neuroinflammation and serotonergic deficits in mice that persist into adulthood

“…The number of 5-HT neurons was reduced in the DRN and accompanied by a reduction in 5-HT expression in the thalamus, ACC and amygdala. These regions were selected because they mediate descending modulation of pain and receive 5-HT input from the DRN (Ab Aziz and Ahmad, 2006;Chao et al, 2021;Duan et al, 2021;Gandhi et al, 2021;Gilpin et al, 2021;Heijmans et al, n.d.;Juarez-Salinas et al, 2019;Li et al, 2019;Price, 2000;Zargarani et al, 2021).…”

Intra-accumbal orexinergic system contributes to the stress-induced antinociceptive behaviors in the animal model of acute pain in rats

“…In the present study, the role of the orexin receptors of the NAc region in the antinociception induced by FSS was assessed, and the blockade of intra-accumbal orexin receptors attenuated antinociception.It has also been found that chemical stimulation of the LH alleviated the sensation of pain in rat models of inflammatory pain (Yazdi, Jahangirvand et al, 2016;Rasouli, Rashvand et al, 2020), neuropathic pain (Rezaee, Salehi et al, 2019;Salehi, Kashfi et al, 2020), and acute pain (Brojeni, Rashvand et al, 2019;Zargarani, Karimi-Haghighi et al, 2021).…”

“…In addition, Park and Weon (2017) declared that orexins are involved in the expression of long-term depression in the dorsal horn of the spinal cord, which might indicate a mechanism for orexin-induced analgesia (Park and Weon, 2017). In the present study, the role of the orexin receptors of the NAc region in the antinociception induced by FSS was assessed, and the blockade of intra-accumbal orexin receptors attenuated antinociception.It has also been found that chemical stimulation of the LH alleviated the sensation of pain in rat models of inflammatory pain (Yazdi, Jahangirvand et al ., 2016; Rasouli, Rashvand et al ., 2020), neuropathic pain (Rezaee, Salehi et al ., 2019; Salehi, Kashfi et al ., 2020), and acute pain (Brojeni, Rashvand et al ., 2019; Zargarani, Karimi-Haghighi et al ., 2021). Previous research has stated the role of the orexin system as an endogenous neuropeptide in numerous functions such as stress (Grafe and Bhatnagar, 2018; Grafe, Eacret et al ., 2018), metabolism of energy (Yamanaka, Beuckmann et al ., 2003) and different animal models of pain modification.…”

“…Furthermore, the neural pathway from LH to VTA and NAc plays a crucial role in pain modification (Mukai, Kim et al ., 2009). Moreover, the results obtained in this study are consistent with previous studies, which have shown that intra-accumbal microinjection of the maximum doses of SB334867 or TCS OX2 29 alone does not have a significant effect on the tail-flick test (Sadeghi, Reisi et al ., 2013; Zargarani, Karimi-Haghighi et al ., 2021). Therefore, NAc orexin receptors do not play a role in pain modulation in normal conditions (Li, Chang et al ., 2021).…”

“…The orexin projections are involved in various behavioral and physiological functions (Sakurai, Amemiya et al ., 1998; Marcus, Aschkenasi et al ., 2001; Sargin, 2019). Previous studies showed orexin receptors are located in the lateral hypothalamic and thalamic nuclei (Haghparast, Fatahi et al ., 2017; Salehi, Kashfi et al ., 2020), locus coeruleus (Safari, Haghparast et al ., 2009, 2011), nucleus accumbens (NAc) (Yazdi, Jahangirvand et al ., 2016; Andreoli, Marketkar et al ., 2017), ventral tegmental area (VTA) (Sadeghi, Reisi et al ., 2013; Ezzatpanah, Babapour et al ., 2016; Haghparast and Rashvand, 2022), hippocampus (Haghparast, Fatahi et al ., 2017; Haghparast, Shafiei et al ., 2018; Brojeni, Rashvand et al ., 2019; Rasouli, Rashvand et al ., 2020; Zargarani, Karimi-Haghighi et al ., 2021), basal ganglia, cerebral cortex, preoptic area, reticular formation (Cluderay, Harrison et al ., 2002; Razavi and Hosseinzadeh, 2017). Indeed, several studies have shown that the orexin system plays an essential role in reward-seeking behaviors (Haghparast, Fatahi et al ., 2017; Zarrabian, Riahi et al ., 2020), sensory modulation (Sakurai, 2014; Andreoli, Marketkar et al ., 2017; Park and Weon, 2017), stress processing (Grafe and Bhatnagar, 2018; Sargin, 2019), endocrine functions (Martyńska, Polkowska et al ., 2006), and pain modulation (Chiou, Lee et al ., 2010; Askari, Oryan et al ., 2021; Li, Chang et al ., 2021).…”