Increased Anxiety-like Behaviors in Adgra1−/− Male But Not Female Mice are Attributable to Elevated Neuron Dendrite Density, Upregulated PSD95 Expression, and Abnormal Activation of the PI3K/AKT/GSK-3β and MEK/ERK Pathways

•ADGRA1 deficiency leads to increased anxiety level in male mice.•ADGRA1 is involved in the regulation of synaptic structure and function.•ADGRA1 negatively regulates the GPCR pathways in amygdalae of male mice.•ADGRA1 modulates anxiety-like behavior in a sex-dependent manner in mice.