Year: 2015
Type: article
Abstract: Oxytocin (OXT) is a nine amino acid neuropeptide associated with prosocial and affiliative behaviour in mammals • OXT has been shown in human studies to increase trust, positive communication, and have a positive impact on social behaviours in autistic individuals • OXT has also shown to increase social behaviour and decrease social avoidance in rodent students • OXT has also been shown to reduce the stress response in terms of attenuation of the hypothalamic-pituitary-adrenal (HPA) axis • Majority of research on behavioural effects of OXT has used central or peripheral administration • The intranasal (i.n.) route of administration is a novel, clinically relevant route of administration that is non-invasive and allows large peptides to cross the blood-brain barrier (BBB) • The prosocial effects of oxytocin make this peptide an ideal candidate for investigation using the intranasal route of administration • There exists a lack of studies in the literature on the effects of intranasal oxytocin on social behaviour and HPA activity in rodentsThe effect of intranasal oxytocin on social interaction and corticosterone levels in ratsSubjects: Male Sprague-Dawley rats (250-300 g) were maintained on a 12h light/dark cycle and given ad libitum access to food and water.Drugs: OXT was dissolved in 0.9% saline and administered intranasally at doses of 5μg/20μL and 20μg/20μL.The same doses were used for intraperitoneal (i.p.) injections but with a volume of 100μL.Controls received an equivalent volume of saline.Procedure: Intranasal administration: i.n.administration was performed as described in Lukas and Neumann (2012).3 days prior to testing, the rats were habituated to i.n.administration.When administering saline or drug, the animal was restrained and the drug was applied bilaterally to the highly innervated rhinarium, avoiding direct application into the nostrils.Social interaction paradigm: The paradigm consists of two days of habituation and one day of testing.• Day 1: Rat + partner placed in the arena for 4 minutes • Day 2: Rat individually placed in the arena for 4 minutes • Day 3: Rats received i.n. or i.p. injection of OXT or saline either 40 minutes (i.n.) or 20 minutes (i.p.) prior to being placed in the arena for 10 minutes A video camera was located above the arena and total time spent engaging in active social interaction was scored.Blood collection for corticosterone analysis: Blood samples were obtained using tail venipuncture right before (0 min), 20, 40, 60, and 120 min after either i.p. or i.n.OXT or saline injections.Two blood droplets were collected on Schleicher and Schuell filter paper, dried at room temperature and then stored at -20°C.Corticosterone levels were determined from the eluted blood sample using a commercial RIA kit (MP biomedical) according to the manufacturer's instructions.
Author: Alisha Awadia
Language: English
Subfield: Endocrine and Autonomic Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2194518189