D2 dopamine receptor activation induces female preference for male song in the monogamous zebra finch.

The evolutionary conservation of neural mechanisms for forming and maintaining pair bonds is unclear. Oxytocin, vasopressin and dopamine (DA) transmitter systems have been shown to be important in pair-bond formation and maintenance in several vertebrate species. We examined the role of dopamine in formation of song preference in zebra finches, a monogamous bird. Male courtship song is an honest signal of sexual fitness; thus, we measured female song preference to evaluate the role of DA in mate selection and pair-bond formation, using an operant conditioning paradigm. We found that DA acting through the D2 receptor, but not the D1 receptor, can induce a song preference in unpaired female finches and that blocking the D2 receptor abolished song preference in paired females. These results suggest that similar neural mechanisms for pair-bond formation are evolutionarily conserved in rodents and birds.

Vitamin D in patients with intellectual and developmental disability in secure in-patient services in the North of England, UK.

Aims and method To assess the benefits of the introduction of routine vitamin D serum sampling for all patients admitted to a secure in-patient hospital in the North of England providing medium security, low security and rehabilitation services for offenders with intellectual and developmental disability. The vitamin D levels of 100 patients were analysed at baseline. Those with insufficient or deficient levels were offered treatment and retested after 1 year. Vitamin D levels were analysed in the context of level of security, seasonality of test and co-prescription of psychotropic medications. RESULTS: Eighty-three per cent of patients had suboptimal vitamin D levels at initial test (41% deficient and 42% insufficient). This was seen among established patients and new admissions. Regression analysis of baseline vitamin D levels revealed no differences for levels of security, seasonality, whether patients were taking antipsychotic or anticonvulsant medication, or length of stay. Patients with deficiency or insufficiency were all offered supplementation. Those who opted in had significantly higher vitamin D levels at follow-up, compared with those who declined treatment. Clinical implications Established and newly admitted patients in our secure mental health services had substantial levels of vitamin D insufficiency. In the light of the morbidities that are associated with deficient vitamin D levels, routine screening and the offer of supplementation is advisable. Declaration of interest None.