Development Of The Nervous System
Neurons are the cells that form our nervous system. They are remarkable cells. They form long extensions, called axons, that function like telephone wires and transmit signals throughout our body that allow us to feel, think and move. These extensions are sometimes incredibly long. Neurons in your eye form the optic nerve, which extends into your brain. One group of neurons forms the sciatic nerve, which stretches from your lower spine all the way down your leg.
Neurons consist of several types. Some neurons receive information from outside the body. These are called sensory neurons, and include those in your eye that respond to light, those in your nose that respond to odors, and those in your skin that respond to touch and temperature. Neurons in our brain interpret the incoming information, allow us to think, and hold our memories. Other neurons, called motor neurons, extend out of our spinal cord, and allow us to move our muscles. For reasons that are not yet understood, Alzheimer's disease affects our brain, but spares our motor neurons. Yet, Amyotropic Lateral Sclerosis causes loss of function of our motor neurons, leading to paralysis, but spares our brain.
Unfortunately, unlike most of our cells, however, neurons cannot regenerate if injured. For example, if you cut your skin, the cells surrounding the cut will begin to divide and patch the cut. Our neurons don't share this ability. This is why a spinal injury can lead to permanent paralysis, and why the progressive loss of neurons in our brain results in memory loss.
Many laboratories, including our own, are seeking methods to coax an injured neuron to grow a new axon, to reconnect or replace a lost neuron. Stem cells may one day provide the ability to replace lost neurons. A serious difficulty is that nervous system connections originally form during embryonic development, when the body is extremely small. In the adult, the new or regrowing axon has to find its way to its "target" which can now be several inches away. This would be like us trying to locate a particular house in the next town without a map or directions.
Our laboratory studies how axons grow and connect with their targets during normal development. This involves coordinated changes in expression of several genes. Proteins made by neurons have to be moved into the growing axon along what are essentially "railroad tracks" and assembled into a scaffold that helps the axon stay connected to its target (the next neuron in a chain, or a muscle). Any errors in these processes will result in failure to locate, or remain connected to, the target, and signals therefore will not be transmitted. Depending upon which neurons fail, this will result in loss of memory or paralysis. Like many laboratories, we can keep neurons alive outside the body in Petri dishes supplied with basic nutrients. This process has allowed scientists, including us, to learn much about how neurons function under normal conditions, and what goes wrong during many diseases and following injury. Continued studies in this area will help us understand how to coax neurons to regrow axons following injury.
Studies in Nervous System Development have been funded by the National Institutes of Health, the National Science foundation.
AGING, ALZHEIMER'S DISEASE AND AMYOTROPIC LATERAL SCLEROSIS
After almost 20 years of laboratory research, we development an inexpensive, vitamin- and nutriceutical-based, "over the counter" formulation that can maintain brain health during hormal aging and delay the loss of neurodegeneration. No prescription is required, so it can be consumed prior to any loss of memory.
Phase I clinical studies with this Formulation were published in 2009 and 2010. We recently completed Phase II studies, which were funded by the Alzheimer's Association. These studies collectively provided evidence that this Formulation was able to maintain, and in some cases improve, memory, daily function and mood. We anticipate publication of these newer results by the end of 2013. This Formulation will be available to the public shortly.
Our published laboratory studies have shown that a component of this formulation was beneficial in a mouse model for motor neuron disease. Whether or not this formulation will also be helpful for Amyotrophic Lateral Sclerosis is a goal of our ongoing and future studies.
These studies have been supported by the Alzheimer's Association, the Amyotrophic Lateral Sclerosis Association, the American Federation for Aging Research, the National Institute for Aging, and the Adelard A & Veleda Lea Roy Foundation.
CONNECTING NEURONS TO COMPUTERS
Our brains receive incredible amounts of information every minute. We have to interpret this information, store it as memories, and choose the correct action. Sometimes, like while driving a car, we must act immediately with no chance for error. The Army is interested in understanding how the brain processes information, and how we can improve our reaction speed while maintaining the correct responses. To study these processes, we place embryonic neurons in Petri dishes that have a grid of 64 electrodes embedded in the bottom. The axons of these neurons connect with each other to form a network much like the developing brain. These electrodes are connected to a powerful series of computers that allow us to record the signals transmitted by neurons. We can also send signals into the network, and view their responses. In collaboration with Professor Holly Yanco and her student Abe Schultz in UMass Lowell's Robotics Laboratory, we have connected these Neuronal Networks to a Robot Arm, which can retrieve objects for a disabled individual or operate machinery. Visit YouTube for a simple demonstration. The screens show streams of signals transmitted from one of our Neuronal Networks. When a large signal is transmitted, it triggers the Robot Arm to move in that direction.
Future studies will feed video camera surveillance signals to this Neuronal Networks, which have been trained to recognize certain images and shapes. If the Network recognizes the on-screen image, it will dictate one series of actions for the the Robot Arm; if the Network does not recognize the image, it will dictate a different action for the Arm.
These studies have been supported by the US Army Research Laboratories.