, 2013) and polymorphisms in human relaxin-3 and RXFP3 associated with metabolic disturbances in patients with schizophrenia treated with antipsychotic drugs (Munro et al., 2012). Thus the study of the NI and relaxin-3 is an exciting new frontier in behavioural neuroscience. A strategy to achieve potent and selective lesioning of target brain structures has been to utilise cell-surface protein binding peptides or antibodies conjugated with saporin, a monomeric ribosomal inactivating protein (Heckers et al., 1994, Li et al., 2008, Thorpe et al., 1985 and Waite et al., 1994). Selectivity is achieved

because, as a ribosomal toxin, the saporin is only toxic when internalised by the corresponding receptor. The corticotropin releasing factor (CRF)–saporin conjugate selleck toxin, used in the present study, is expected to selectively ablate CRF1 expressing cells (Hummel et al., 2010 and Maciejewski-Lenoir et al., 2000). On the premise that relaxin-3 expressing neurons in the NI predominantly co-express CRF1 receptors (Tanaka et al., 2005), the present investigation attempted to establish a method for selective ablation of the NI using the CRF–saporin conjugate. Out of the total of 76 rats that underwent the surgical procedure, 43 receiving CRF–saporin and 33 serving as various controls, no mortality attributable to the CRF–saporin

lesion was observed. Two rats were euthanised under veterinary advice because of an unrelated infection and a case of malocclusion of the incisors. In one experiment, post-surgical weight gain was monitored daily Myosin over 14 days but there was no significant difference in weight gain Veliparib mouse between the sham- and NI-lesioned rats (n=8 per group, n.s.). To determine an appropriate dose of CRF–saporin, 40×, 20× and 10× dilutions of the original stock solution of CRF–saporin were infused separately into the NI of rats. CRF1 immunofluorescence staining results showed that infusion of 172 ng of CRF–saporin was sufficient to bring about a loss in CRF1 expressing cells in the NI (Fig. 1A–D). This dose is therefore used for the subsequent experiments. The specificity

of the CRF RI/II antibody was assessed by preabsorption of the antibody with the CRF blocking peptide, which abolished CRF1 staining in the NI of naïve rats (Fig. 2A–B). RT-PCR analysis showed that the NI-lesioned rats had a significant reduction in the expression of CRF1 receptors compared to the sham-lesioned group. As hypothesised, corresponding decreases in the expression of relaxin-3 and GAD65 were also observed in the NI-lesioned rats (Fig. 3A). TPH2 expression was unaltered in both the sham and NI-lesioned group as seen in the densitometry analysis of the PCR bands (Fig. 3B). In a separate group of animals, a real-time PCR analysis showed that the CRF1, relaxin-3 and GAD65 mRNA expression in NI-lesioned rats was 0.004-, 0.02- and 0.