Alzheimer's Disease (AD) – is the most common form of dementia.  It affects memory, thinking, behavior and gradually gets worse over time.  The cause is not known, but genetic factors can increase the risk.  AD is characterized by progressive loss of nerve cells and their interconnections in specific regions of the brain.

Amyotrophic Lateral Sclerosis (ALS) often referred to as "Lou Gehrig's Disease," is a progressive neurodegenerative disease that affects nerve cells in the brain (upper motor neurons) and the spinal cord (lower motor neurons) that control muscle movement.  Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body.  The progressive degeneration of the motor neurons in ALS eventually leads to the death of these neurons.  The astrocytes of ALS patients are diseased, which contributes to motor neuron death.  When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost.  With voluntary muscle action progressively affected, patients in the later stages of the disease may become totally paralyzed and die from respiratory failure as the muscles that control breathing can no longer function.

Astrocytes are one type of support cell of the brain and spinal cord that provide many essential functions that are needed by neurons.  Astrocytes provide multiple mechanisms of neuroprotection, including production of important growth factors as well as removal of substances that are toxic to neurons.

Axon is a long, slender protrusion from the body of a nerve cell (called a neuron), that is the primary transmission line of the neuron.  It conducts electrical impulses away from the neuron's cell body, and makes contact with other cells (neurons or muscle cells) at specialized sites called synapses where chemical messengers can be exchanged between the cells to form circuits.  Axons can be up to a meter in length in humans.  Bundles of axons form nerves. 

Central Nervous System (CNS) – is the part of the nervous system that consists of the brain, spinal cord and optic nerve.

Demyelinating Diseases are any disease of the nervous system in which the insulating myelin sheath (which is part of a living cell, the oligodendrocyte) of neurons is damaged or destroyed.  This impairs the conduction of signals in the affected nerves, causing impairment in sensation, movement, cognition, or other functions depending on which nerves are involved.

Glial Restricted Progenitor Cells (GRPs) are a renewable neural cell population of the CNS that gives rise to the cells that support the neurons - the astrocytes and oligodendrocytes (the glial cells).   Q Therapeutics has trademarked these human GRPs as Q-Cells®.  Q-Cells act as ‘mini-factories’ that can produce growth factors, provide toxin removal, nutritional support and the insulating myelin sheath that may offer both neuroprotection as well as restoration of function to damaged and diseased neurons.

Hematopoietic Stem Cell (HSC)s are cells isolated from the blood or bone marrow that give rise to all types of red and white blood cells.  HSC can self-renew, can differentiate to a variety of specialized cells, can mobilize out of the bone marrow into circulating blood, and can undergo programmed cell death, called apoptosis.  A balance between renewal and apoptosis occurs in healthy individuals to maintain a steady level of HSCs.

Huntington’s Disease Huntington’s disease is a fatal neurodegenerative disease caused by a hereditary mutation in the Huntington gene.  Symptoms are normally manifested in adult life, resulting in decline in muscle coordination and cognitive function, as well as psychiatric problems, with death usually ensuing after 20 years from onset of visible symptoms.

Mesenchymal Stem Cell (MSC)s – are adult stem cells traditionally found in the bone marrow.  However, mesenchymal stem cells can also be isolated from other tissues including cord blood, peripheral blood, fat tissue, placenta and menstrual blood.  Multipotent stem cells, MSCs differentiate to form adipocytes, cartilage, bone, tendons, muscle, and skin.  Mesenchymal stem cells are a distinct entity to the mesenchyme, embryonic connective tissue which is derived from the mesoderm and differentiates to form hematopoietic stem cells.

Multiple Sclerosis (MS) is a disease in which the insulating myelin sheath surrounding the axons of neurons of the central nervous system (brain and spinal cord) is destroyed, due to damage to the cells (oligodendrocytes ) that form this living myelin sheath.  The damage and death of the oligodendrocytes is caused by the body’s own immune system attacking these cells in what is classified as an autoimmune disease.  Current treatments of MS are aimed at slowing this autoimmune attack on the oligodendrocytes, thus slowing the disease progression of MS.  These treatments slow the destruction and loss of the myelin sheath, but do not repair the damage.

Myelin Sheath is the insulating envelope of myelin that surrounds the axon, the individual components of a nerve fiber, and that facilitates the transmission of nerve impulses.  The myelin sheath (also called medullary sheath) in the CNS is formed from extensions of the oligodendrocytes and in the peripheral nervous system (PNS) from extensions of the Schwann cells.

Myelination is the formation of an insulating white sheath (myelin sheath) around certain nerve fibers.  The myelin sheath in the CNS is composed of extensions of a living cell, the oligodendrocyte.  Damage to the oligodendrocyte results in damage and loss of the myelin sheath, causing neurological disease, as in multiple sclerosis.

Neural Stem Cells (NSCs) are multipotent cells that generate the main cell types of the nervous system.  Stem cells are characterized by their capability to self-renew and to differentiate into multiple cell types via exogenous stimuli from their environment.  NSCs can differentiate into neurons and glial cells (astrocytes, and oligodendrocytes).

Neurons are any of the impulse-conducting cells that reside within the brain, spinal column, and peripheral nervous system, consisting of a nucleated cell body with one or more dendrites and a single axon.  Neurons are also called nerve cells.

Neuroprotection is protection of neurons against injury or degeneration; several different mechanisms are involved in neuroprotections.  For central nervous system (CNS) disorders, neuroprotection is being explored to treat neurodegenerative diseases (e.g., ALS, MS, Parkinson’s disease, Alzheimer’s disease) and neurological injury (e.g., stroke, traumatic brain injury, spinal cord injury).  Neuroprotection can prevent or slow disease progression by preventing death of neurons, and can also lead to restoration of function to damaged neurons, for example by remyelination.

Oligodendrocyte is a glial cell of the central nervous system that provides the insulating myelin sheath around axons. In diseases such as MS, the oligodendrocytes are destroyed by the body’s own immune system, resulting is loss of the myelin sheath.  Oligodendrocytes are one of the types of glial cells produced from human GRPs (trademarked as Q-Cells®).

Parkinson's Disease is a disease of the brain that leads to shaking (tremors) and difficulty with walking, movement, and coordination.  Parkinson's disease is caused by the progressive loss of specific nerve cells in the brain that make dopamine.  Dopamine is a neurotransmitter, and when it is not available, the nerve cells in that part of the brain cannot properly send messages, which leads to movement disorders including rigidity, tremor, and slowness of movement.  It is not known what causes Parkinson’s disease.

Progenitor Cells are cells that can generate only certain cell types in a tissue, not all the cells of that tissue.  For example, glial restricted progenitor cells (GRPs) can only produce other glial cells, including self-replication to form more GRPs as well as differentiation into mature glial cells - astrocytes and oligodendrocytes - but not into neurons.

Remyelination is a term for the re-generation of the nerve's myelin sheath after it has been damaged by diseases such as multiple sclerosis (MS) and transverse myelitis (TM), or by injury (e.g., spinal cord injury, stroke).  Remyelination in the CNS can only occur when oligodendrocytes send out extensions from their cell body that then surrounds the axons of neurons.  The myelin sheath is an extension of the living oligodendrocyte cell.

Schwann Cells are the principal glial cells of the peripheral nervous system (PNS). Analogous to the oligodendrocyte cells in the central nervous system, the Schwann cells function to support neurons in the PNS.  There are two types of Schwann cell, myelinating and nonmyelinating.  Myelinating Schwann cells wrap projections from their cell body around axons of motor and sensory neurons to form the myelin sheath in the PNS.

Spinal Cord Injury (SCI) – is the result of an insult to the spinal cord causing a change, either temporary or permanent, in its normal motor, sensory, or autonomic function.  Depending on the extent of the original spinal cord injury, there can be some recovery of function, but many patients with spinal cord injury have permanent and often devastating neurologic deficits and disability. 

Stem Cells are cells found in all multicellular organisms.  They can divide (through mitosis) and differentiate into diverse specialized cell types, and can also self-renew to produce more stem cells.  In mammals, there are two broad types of natural stem cells: embryonic stem cells, which are isolated from the inner cell mass of early stage embryos (blastocysts) and which are pluripotent, i.e., have the potential to form all cell types in the body; and adult stem cells, which are found in various tissues and are multipotent, i.e., have the potential to form the cell types of that type of tissue but not of other tissue types.  Stem cells and progenitor cells act as a repair system for the body, replenishing tissues.  Induced pluripotent stem cells (iPSC) are stem cells created in the laboratory from adult specialized cells (such as skin or blood cells) that have been artificially manipulated by the introduction of certain genes to de-differentiate into pluripotent stem cells.  iPSC are being studied as a new source of a pluripotent stem cell, to produce other desired mature cell types for treatment of disease.

Transverse Myelitis (TM) is a neurological disorder caused by acute inflammation across a segment of the spinal cord. This acute inflammatory attack can damage or destroy the oligodendrocytes that form the myelin sheath, the fatty insulating substance that covers nerve cell fibers (axons).  This damage leads to loss of proper function of these nerve fibers, and can lead to loss of various functions including bowel and bladder control, sensory function and the ability to walk.  The origin of the acute inflammatory attack that causes TM is not known.  Transverse myelitis has similarities to multiple sclerosis in that attack on oligodendrocytes results in nerve damage due to loss of myelin, with loss of axons occurring secondarily, but also has differences from MS in that it occurs in only one location in the spinal cord and is not recurring.  For these reasons, transverse myelitis may provide a good starting point to assess benefits of remyelination that can then be studied for treatment of other demyelinating diseases such as multiple sclerosis.