Activation of Dopamine D1 Receptors at the Axon Initial Segment-Like Process of Retinal AII Amacrine Cells Modulates Action Potential Firing.

Dopamine is an important neuromodulator found throughout the central nervous system that can influence neural circuits involved in sensory, motor, and cognitive functions. In the retina, dopamine is released by specific amacrine cells and plays a role in reconfiguring circuits for photopic vision. This adaptation takes place both in photoreceptors and at postreceptoral sites.

CLN3 disease disrupts very early postnatal hippocampal maturation.

CLN3 disease or juvenile neuronal ceroid lipofuscinosis (Batten disease), is a progressive, severe, neurodegenerative, lysosomal storage disorder. Previous studies have demonstrated that network-level excitability differences are present in mouse models prior to significant lysosomal storage accumulation. Here we sought to identify the earliest biochemical and functional markers of disease in the hippocampus, a brain region important in learning and memory and implicated in CLN3 disease.

Morphological properties of the axon initial segment-like process of AII amacrine cells in the rat retina.

Signal processing within the retina is generally mediated by graded potentials, whereas output is conveyed by action potentials transmitted along optic nerve axons. Among retinal neurons, amacrine cells seem to be an exception to this general rule, as several types generate voltage-gated Na (Na ) channel-dependent action potentials. The AII, a narrow-field, bistratified axon-less amacrine cell found in mammalian retinas, displays a unique process that resembles an axon initial segment (AIS), with expression of Na channels colocalized with the cytoskeletal protein ankyrin-G, and generates action potentials.

Learning Induces Transient Upregulation of Brevican in the Auditory Cortex during Consolidation of Long-Term Memories.

It is a daily challenge for our brains to establish new memories via learning while providing stable storage of remote memories. In the adult vertebrate brain, bimodal regulation of the extracellular matrix (ECM) may regulate the delicate balance of learning-dependent plasticity and stable memory formation. Here, we trained adult male mice in a cortex-dependent auditory discrimination task and measured the abundance of ECM proteins brevican (BCN) and tenascin-R over the course of acquisition learning, consolidation, and long-term recall in two learning-relevant brain regions; the auditory cortex and hippocampus.

Mechanisms of cAMP-induced sustained activation of extracellular signal-regulated kinase in the hippocampus.

Protein phosphorylation is known to regulate synaptic plasticity and memory. Protein kinases including protein kinase A and extracellular signal-regulated kinase (ERK) play important roles in these processes. Forskolin, a protein kinase A activator, induces long-term potentiation (LTP) in the hippocampus.