NRG1-ErbB4 signaling in the medial amygdala controls mating motivation in adult male mice.

Motivation-driven mating is a basic affair for the maintenance of species. However, the underlying molecular mechanisms that control mating motivation are not fully understood. Here, we report that NRG1-ErbB4 signaling in the medial amygdala (MeA) is pivotal in regulating mating motivation. NRG1 expression in the MeA negatively correlates with the mating motivation levels in adult male mice. Local injection and knockdown of MeA NRG1 reduce and promote mating motivation, respectively. Consistently, knockdown of MeA ErbB4, a major receptor for NRG1, and genetic inactivation of its kinase both promote mating motivation. ErbB4 deletion decreases neuronal excitability, whereas chemogenetic manipulations of ErbB4-positive neuronal activities bidirectionally modulate mating motivation. We also identify that the effects of NRG1-ErbB4 signaling on neuronal excitability and mating motivation rely on hyperpolarization-activated cyclic nucleotide-gated channel 3. This study reveals a critical molecular mechanism for regulating mating motivation in adult male mice.

Neogenin in Amygdala for Neuronal Activity and Information Processing.

Fear learning and memory are vital for livings to survive, dysfunctions in which have been implicated in various neuropsychiatric disorders. Appropriate neuronal activation in amygdala is critical for fear memory. However, the underlying regulatory mechanisms are not well understood. Here we report that Neogenin, a DCC (deleted in colorectal cancer) family receptor, which plays important roles in axon navigation and adult neurogenesis, is enriched in excitatory neurons in BLA (Basolateral amygdala). Fear memory is impaired in male Neogenin mutant mice. The number of cFos+ neurons in response to tone-cued fear training was reduced in mutant mice, indicating aberrant neuronal activation in the absence of Neogenin. Electrophysiological studies show that Neogenin mutation reduced the cortical afferent input to BLA pyramidal neurons and compromised both induction and maintenance of Long-Term Potentiation evoked by stimulating cortical afferent, suggesting a role of Neogenin in synaptic plasticity. Concomitantly, there was a reduction in spine density and in frequency of miniature excitatory postsynaptic currents (mEPSCs), but not miniature inhibitory postsynaptic currents, suggesting a role of Neogenin in forming excitatory synapses. Finally, ablating Neogenin in the BLA in adult male mice impaired fear memory likely by reducing mEPSC frequency in BLA excitatory neurons. These results reveal an unrecognized function of Neogenin in amygdala for information processing by promoting and maintaining neurotransmission and synaptic plasticity and provide insight into molecular mechanisms of neuronal activation in amygdala.SIGNIFICANCE STATEMENT Appropriate neuronal activation in amygdala is critical for information processing. However, the underlying regulatory mechanisms are not well understood. Neogenin is known to regulate axon navigation and adult neurogenesis. Here we show that it is critical for neurotransmission and synaptic plasticity in the amygdala and thus fear memory by using a combination of genetic, electrophysiological, behavioral techniques. Our studies identify a novel function of Neogenin and provide insight into molecular mechanisms of neuronal activation in amygdala for fear processing.

[Effects of hnRNP B1-specific siRNA on the expression of hnRNP B1 in lung cancer tissues in vivo].

OBJECTIVE: To measure the effect of the eukaryotic expression vector of siRNA specific for hnRNP B1 on the expression of hnRNP Bx in lung cancer tissues in vivo. METHODS: The eukaryotic expression vector of siRNA specific for hnRNP B1 was inoculated to nude mice with lung cancers. The mRNA and protein expressions of hnRNP B1 in the lung cancer tissues of the nude mice were detected by RT-PCR and Western blot. The optimal conditions for the expressions were identified. RESULTS: The eukaryotic expression vector of siRNA specific for hnRNP B1 inhibited the mRNA and protein expressions at 40 days after the inoculation. However, the inhibitive effect disappeared at 60 days after the inoculation. CONCLUSION: The expression of hnRNP B1 gene in A549 cells can be inhibited by hnRNP Br-specific siRNA expression vectors.