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The olfactory bulb differs from other brain regions by its use of bidirectional synaptic transmission at dendrodendritic reciprocal synapses. These reciprocal synapses provide tight coupling of inhibitory feedback from granule cell interneurons to mitral cell projection neurons in the accessory olfactory bulb (AOB), at the first stage of vomeronasal processing. It has been proposed that both the mGluR2 agonist DCG-IV and noradrenaline promote mate recognition memory formation by reducing GABAergic feedback on mitral cells. The resultant mitral cell disinhibition is thought to induce a long-lasting enhancement in the gain of inhibitory feedback from granule to mitral cells, which selectively gates the transmission of the learned chemosensory information. However, we found that local infusions of both noradrenaline and DCG-IV failed to disinhibit AOB neural activity in urethane-anaesthetised mice. DCG-IV infusion had similar effects to the GABA(A) agonist isoguvacine, suggesting that it increased GABAergic inhibition in the AOB rather than reducing it. Noradrenaline infusion into the AOB also failed to disinhibit mitral cells in awake mice despite inducing long-term increases in power of AOB local field potentials, similar to those observed following memory formation. These results suggest that mitral cell disinhibition is not essential for the neural changes in the AOB that underlie mate recognition memory formation in mice.

Purpose To evaluate inhibition of Micro-Fibrillar Associated Protein 4 (MFAP4) on choroidal neovascularization (CNV) in a mouse model of age-related macular degeneration (AMD). Methods All experiments complied with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. Female C57BL/6J mice were subjected to laser-induced CNV, and intravitreally injected with either 1 µg ±MFAP4, 5 µg ±MFAP4, 1 µg mouse IgG or 1 µg ±VEGF-A on day 0 and day 7. Fluorescein angiography (FA) was undertaken at day 7 and day 14, and choroids stained for inflammation (CD45) and vasculature (isolectin B4, IB4). Results FA showed that injection of αMFAP4 reduced average lesion size and density on day 7 compared to IgG (p