Ephron Rosenzweig, Ph.D.
Assistant Project Scientist

Current Research

My research addresses two different approaches to spinal cord repair: regeneration of cut axons and sprouting of intact axons. Although regeneration of cut axons is the ultimate goal of spinal cord repair research, data from our lab and others suggests that a more practical approach may be to stimulate the compensatory sprouting of axons spared by the initial injury. These axons could form new circuitry beyond the lesion, potentially restoring function. Because even severe human spinal cord injuries (SCIs) generally leave some axons intact, many people currently living with SCI could benefit from such a treatment.

A pictorial summary of some of the factors involved in spinal cord injury research. Click to view complete figure in a new window.

Our attempts to induce regeneration and/or sprouting focus on viral-vector delivery of neurotrophins. Neurotrophins, such as BDNF and NT-3, are proteins that influence the growth, survival, and differentiation of neural cells. We use viral vectors (adeno-associated virus, lentivirus) to transfect the cells of the host tissue, causing the subject's own cells to produce high concentrations of the desired neurotrophin. We then examine different projection systems, most notably the corticospinal, raphespinal, coerulospinal, and reticulospinal systems, for signs of regeneration or sprouting.

Recently, we have begun combining neurotrophic delivery with treatments that have shown promise in other laboratories. These treatments include: enzymatic degradation of inhibitory chondroitin sulfate proteoglycans (CSPGs), modulation of cyclic nucleotide levels in regenerating cells, and impantation of agarose scaffolds to direct regenerating axons across the lesion site in a more orderly and efficient manner. In an attempt to increase the clinical relevance of our work, we have moved from rodent models of SCI to animal models that better reproduce the conditions of human SCI. In addition, we have begun testing our therapies on models of chronic SCI, in which intervention is delayed until 6 months after injury.


Recent Publications

Taylor SJ, Rosenzweig ES, McDonald JW 3rd, Sakiyama-Elbert SE. Delivery of neurotrophin-3 from fibrin enhances neuronal fiber sprouting after spinal cord injury. Journal of Controlled Release (2006): Jul 20;113(3):226-35.

Rosenzweig ES, McDonald JW. Rodent models for treatment of spinal cord injury: research trends and progress toward useful repair. Current Opinion in Neurology (2004): Apr; 17(2):121-31.

Rosenzweig ES, Barnes CA. Impact of aging on hippocampal function: plasticity, network dynamics, and cognition. Progress in Neurobiology (2003): Feb; 69(3):143-79.

Rosenzweig ES, Redish AD, McNaughton BL, Barnes CA. Hippocampal map realignment and spatial learning. Nature Neuroscience (2003): Jun; 6(6):609-15.

Rosenzweig ES, Barnes CA, McNaughton BL. Making room for new memories. Nature Neuroscience (2002): Jan:5(1):6-8.

Redish AD, Battaglia FP, Chawla MK, Ekstrom AD, Gerrard JL, Lipa P, Rosenzweig ES, Worley PF, Guzowski JF, McNaughton BL, Barnes CA. Independence of firing correlates of anatomically proximate hippocampal pyramidal cells. Journal of Neuroscience (2001): Mar 1:21(5):RC134.

Redish AD, Rosenzweig ES, Bohanick JD, McNaughton BL, Barnes CA. Dynamics of hippocampal ensemble activity realignment: time versus space. Journal of Neuroscience (2000): Dec 15;20(24):9298-309.

Rosenzweig ES, Rao G, McNaughton BL, Barnes CA. Role of temporal summation in age-related long-term potentiation-induction deficits. Hippocampus (1997): 7(5):549-58.