Oxytocin and vasopressin in non-human primates

Neuroanatomy of OT and AVP in non-human primates OT and AVP immunoreactive cells and fibers in the brain, spinal cord, and pineal gland Atunes and Zimmerman (1978) performed one of the first studies using antisera to AVP, OT, and neurophysins to visualize the OT and AVP system in the hypothalamus of non-human primates. They found that there were OT-immunoreactive cells (-ir) and AVP-ir neurons in the paraventricular nucleus (PVN) and the supraoptic nucleus of the hypothalamus (SON). Additionally, cells containing OT and AVP also contained the neurophysin estrogen-stimulated neurophysin (ESN) and nicotine-stimulated neurophysin (NSN), respectively. These two neurophysins are transporter molecules that are important for the trafficking of OT and AVP molecules after translation (de Bree, 2000). OT-ESN cells and AVP-NSN cells were evenly distributed in the PVN while they were localized within the SON. Subsequent studies examining other non-human primate species found similar results. Currently, OT and AVP neurons have been visualized in three species of macaque (rhesus macaques: Macaca mulatta, crab-eating macaques: Macaca fasciculata, and Japanese macaques: Macaca fuscata)(Atunes and Zimmerman, 1978; Caffé et al., 1989; Ginsberg et al., 1994; Ichimiya et al., 1988; Kawata and Sano, 1982; Sladek and Zimmerman, 1982; Sofroniew et al., 1981), the New World squirrel monkey (Saimiri sciureus) (Sofroniew et al., 1981) and the common marmoset (Callithrix jacchus) (Wang et al., 1997a; Wang et al., 1997b). While there is great similarity between species in the location of OT and AVP cell bodies and fibers, species differences do appear to exist (Table 16.1 details abbreviations; Tables 16.2 and 16.3). It is sometimes difficult to determine whether these species differences are genuine due to the fact that different studies focus on specific brain areas, particular parts of cells, and use different methodologies

Oxytocin and vasopressin in non-human primates

Neuroanatomy of OT and AVP in non-human primates OT and AVP immunoreactive cells and fibers in the brain, spinal cord, and pineal gland Atunes and Zimmerman (1978) performed one of the first studies using antisera to AVP, OT, and neurophysins to visualize the OT and AVP system in the hypothalamus of non-human primates. They found that there were OT-immunoreactive cells (-ir) and AVP-ir neurons in the paraventricular nucleus (PVN) and the supraoptic nucleus of the hypothalamus (SON). Additionally, cells containing OT and AVP also contained the neurophysin estrogen-stimulated neurophysin (ESN) and nicotine-stimulated neurophysin (NSN), respectively. These two neurophysins are transporter molecules that are important for the trafficking of OT and AVP molecules after translation (de Bree, 2000). OT-ESN cells and AVP-NSN cells were evenly distributed in the PVN while they were localized within the SON. Subsequent studies examining other non-human primate species found similar results. Currently, OT and AVP neurons have been visualized in three species of macaque (rhesus macaques: Macaca mulatta, crab-eating macaques: Macaca fasciculata, and Japanese macaques: Macaca fuscata)(Atunes and Zimmerman, 1978; Caffé et al., 1989; Ginsberg et al., 1994; Ichimiya et al., 1988; Kawata and Sano, 1982; Sladek and Zimmerman, 1982; Sofroniew et al., 1981), the New World squirrel monkey (Saimiri sciureus) (Sofroniew et al., 1981) and the common marmoset (Callithrix jacchus) (Wang et al., 1997a; Wang et al., 1997b). While there is great similarity between species in the location of OT and AVP cell bodies and fibers, species differences do appear to exist (Table 16.1 details abbreviations; Tables 16.2 and 16.3). It is sometimes difficult to determine whether these species differences are genuine due to the fact that different studies focus on specific brain areas, particular parts of cells, and use different methodologies

The effects of morphine, naloxone, and κ opioid manipulation on endocrine functioning and social behavior in monogamous titi monkeys (Callicebus cupreus).

The μ opioid receptor (MOR) and κ opioid receptor (KOR) have been implicated in pair-bond formation and maintenance in socially monogamous species. Utilizing monogamous titi monkeys (Callicebus cupreus), the present study examined the potential role opioids play in modulating the response to separation, a potent challenge to the pair-bond. In Experiment 1, paired male titi monkeys were separated from their pair-mate for 30-min and then received saline, naloxone (1.0mg/kg), morphine (0.25mg/kg), or the KOR agonist, U50,488 (0.01, 0.03, or 0.1mg/kg) in a counter-balanced fashion, immediately prior to a 30-min reunion with their mate. Blood samples were collected immediately prior to and after the reunion. Males receiving morphine approached females less, initiated contact less, and females broke contact with the males less. The increase in cortisol in response to naloxone was greater compared to vehicle, and the increase in cortisol in response to the high dose of U50,488 compared to vehicle approached significance. In Experiment 2, paired males were treated with the KOR antagonist, GNTI (0.1, 0.3, or 1.0mg/kg), or saline 24h prior to a 60-min separation from their mate. Blood samples were collected at the time of injection and immediately before and after separation. Administration of the low dose of GNTI decreased the locomotor component of the separation response compared to vehicle. The present study found that the opioid system is involved in both the affiliative and separation distress components of a pair-bond, and these components are regulated by different opioid receptors

μ and κ opioid receptor distribution in the monogamous titi monkey (Callicebus cupreus): implications for social behavior and endocrine functioning.

The opioid system is involved in infant-mother bonds and adult-adult bonds in many species. We have previously shown that μ opioid receptors (MORs) and κ opioid receptors (KORs) are involved in regulating the adult attachment of the monogamous titi monkey. The present study sought to determine the distribution of MOR and KOR in the titi monkey brain using receptor autoradiography. We used [(3)H][D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO) to label MORs and [(3)H]U69,593 to label KORs. MOR binding was heterogeneous throughout the titi monkey brain. Specifically, MOR binding was observed in the cingulate gyrus (CG), striatum, septal regions, diagonal band, amygdala, hypothalamus, hippocampus, and thalamus. Binding was particularly dense in the septum, medial amygdala, paraventricular nucleus of the hypothalamus, mediodorsal thalamus with moderate binding in the nucleus accumbens. Consistent with other primate species, MOR were also observed in "neurochemically unique domains of the accumbens and putamen" (NUDAPs). In general KOR binding was more homogenous. KORs were primarily found in the CG, striatum, amygdala and hippocampus. Dense KOR binding was observed in the claustrum. Relative MOR and KOR binding in the titi monkey striatum was similar to other humans and primates, but was much lower compared to rodents. Relative MOR binding in the titi monkey hypothalamus was much greater than that found in rodents. This study was the first to examine MOR and KOR binding in a monogamous primate. The location of these receptors gives insight into where ligands may be acting to regulate social behavior and endocrine function

μ and κ opioid receptor distribution in the monogamous titi monkey (Callicebus cupreus): implications for social behavior and endocrine functioning.

The opioid system is involved in infant-mother bonds and adult-adult bonds in many species. We have previously shown that μ opioid receptors (MORs) and κ opioid receptors (KORs) are involved in regulating the adult attachment of the monogamous titi monkey. The present study sought to determine the distribution of MOR and KOR in the titi monkey brain using receptor autoradiography. We used [(3)H][D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO) to label MORs and [(3)H]U69,593 to label KORs. MOR binding was heterogeneous throughout the titi monkey brain. Specifically, MOR binding was observed in the cingulate gyrus (CG), striatum, septal regions, diagonal band, amygdala, hypothalamus, hippocampus, and thalamus. Binding was particularly dense in the septum, medial amygdala, paraventricular nucleus of the hypothalamus, mediodorsal thalamus with moderate binding in the nucleus accumbens. Consistent with other primate species, MOR were also observed in "neurochemically unique domains of the accumbens and putamen" (NUDAPs). In general KOR binding was more homogenous. KORs were primarily found in the CG, striatum, amygdala and hippocampus. Dense KOR binding was observed in the claustrum. Relative MOR and KOR binding in the titi monkey striatum was similar to other humans and primates, but was much lower compared to rodents. Relative MOR binding in the titi monkey hypothalamus was much greater than that found in rodents. This study was the first to examine MOR and KOR binding in a monogamous primate. The location of these receptors gives insight into where ligands may be acting to regulate social behavior and endocrine function