Many neurons that contain a classical neurotransmitter also contain modulatory peptides, but it has been difficult to establish unequivocally that these peptides are functional cotransmitters. Here, we provide evidence for functional cotransmission in a neuromuscular system of Aplysia. Using immunocytochemical techniques, we localize members of two peptide families, the small cardioactive pepti...

Successful regeneration of damaged neurons depends on the coordinated expression of neuron-intrinsic genes. At present however, there is no comprehensive view of the transcriptional regulatory mechanisms underlying neuronal regeneration. We used high-content cellular screening to investigate the functional contribution of 62 transcription factors to regenerative neuron outgrowth. Ten transcript...

How aging impacts axon regeneration after CNS injury is not known. We assessed the impact of age on axon regeneration induced by Pten deletion in corticospinal and rubrospinal neurons, two neuronal populations with distinct innate regenerative abilities. As in young mice, Pten deletion in older mice remains effective in preventing axotomy-induced decline in neuron-intrinsic growth state, as ass...

In contrast to mammals, salamanders and teleost fishes can efficiently repair the adult brain. It has been hypothesised that constitutively active neurogenic niches are a prerequisite for extensive neuronal regeneration capacity. Here, we show that the highly regenerative salamander, the red spotted newt, displays an unexpectedly similar distribution of active germinal niches with mammals under...

Patterns of neuronal differentiation and axon outgrowth were examined in regenerated neural tissue of the hindbrain of the chicken embryo. Specific regions of the hindbrain neural tube corresponding to identified rhombomeres were selectively removed unilaterally by microsurgery. Of the embryos that survived, about 35% exhibited regulative regeneration, wherein the missing hemi-rhombomere was re...

Previous studies demonstrated that Schwann cells (SCs) express distinct motor and sensory phenotypes, which impact the ability of these pathways to selectively support regenerating neurons. In the present study, unbiased microarray analysis was used to examine differential gene expression in denervated motor and sensory pathways in rats. Several genes that were significantly upregulated in eith...

The Nogo-66 receptor (NgR) plays a critical role in restricting axon regeneration in the central nervous system. This inhibitory action is in part mediated by a neuronal receptor complex containing p75NTR, a multifunctional receptor also well known to trigger cell death upon binding to neurotrophins such as NGF. In the present study, we show that Pep4 and NEP1-40, which are two peptides derived...

In the bone marrow, there are certain populations of stem cell sources with the capacity to differentiate into several different types of cells. Ideally, cell transplants would be readily obtainable, easy to expand and bank, and capable of surviving for sufficient periods of time. Bone marrow mesenchymal stem cells (BM-MSCs) possess all of these characteristics. One of the most important benefi...

Neuropeptide synthesis was determined for individual identified ventral-cluster neurons in the buccal ganglia of Aplysia. Each of these cells was shown to be a motor neuron that innervates buccal muscles that generate biting and swallowing movements during feeding. Individual neurons were identified by a battery of physiological criteria and stained with intracellular injection of a vital dye, ...