Much of what has been learned about the human brain has been discovered from research on the rat brain. Though smaller and less complex than that of humans, the rat brain is extremely useful as a subject of study because most regions of the brain are essentially the same among mammalian species. The rat brain has been heavily employed as an animal model for various neurological diseases, such as Parkinson’s disease. In fact, it was studies of rats that led to the fundamental discovery that the Parkinson’s is caused by the loss of dopamine within the brain. Research with the rodents has also been critical in testing new drug treatments for the disease, as well as investigations of other potential therapeutic approaches, such as gene therapy.

A number of innovative experiments have been devised in an attempt to develop a better understanding of how learning takes place at a cellular level in brain tissue. One unusual experiment involves utilizing thousands of rat neurons in a Petri dish to create art. Carried out by researchers in the United States and Australia, the neurons are thousands of miles away from a robotic arm that holds a set of three markers above a canvas. A system of electrodes connects the neurons to a computer, which is linked to another computer controlling the robotic arm via the Internet. Signals sent by the neurons in response to stimuli in their environment control the movement of the arm, and thus the drawings that are produced as the markers progress across the canvas.

Myelin basic protein, which is expressed by myelinated nerve fibers, and glial fibrillary acidic protein, a type III intermediate filament protein found primarily in astroglia, were immunofluorescently labeled in the rat brain sagittal tissue section presented above by treating the specimen with a cocktail of mouse anti-myelin BP and rabbit anti-GFAP primary antibodies followed by goat anti-mouse and anti-rabbit secondary antibodies conjugated to Alexa Fluor 488 and Alexa Fluor 568, respectively. Hoechst 33342, a dsDNA-interactive agent, was utilized to target cell nuclei. Finally, Hoechst 33342 was employed to counterstain cell nuclei. Nuclear DNA was counterstained with Hoechst 33342. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.

Distribution of Myelin Basic Protein and Glial Fibrillary Acidic Protein in Rat Brain Tissue - Cultured rat brain cells are being employed at the University of Florida to pilot a simulated plane. The experiment, designed by biomedical engineering professor Thomas DeMarse, entails 25,000 cortical neurons extracted from a rat embryo that were placed on a multi-electrode array. The neurons established their own connections soon after they were plated, essentially forming a living computation device, or brain.

Horizontal Section of Rat Brain Immunofluorescently Labeled for Phosphorylated Neurofilaments - A wide variety of diseases can affect the brain, many of which are caused by bacterial or viral infections. One of the best known of such diseases is meningitis, an acute inflammation of the membranes encasing the brain and spinal cord. Meningitis can be caused by bacteria, viruses, fungi, or other organisms that enter the bloodstream. Symptoms of meningitis often include headache, a stiff neck, and sensitivity to light, as well as muscle pain, chills, and fever.

Brain Tissue Sample Triple Labeled with Alexa Fluor 488, Alexa Fluor 568, and Hoechst 33342 - Consuming brain or other nerve tissue is associated with certain health risks, but has been practiced in various human cultures, especially as part of mourning rituals. The accidental consumption of nerve tissue may also occur if the material is unknowingly introduced into ground meats. Prion diseases are spread when infected nervous tissue is consumed.

Targeting Neurofilaments and Astroglia in Rat Brain Sections - Two different basic types of cells compose the brain: neurons and glia. Neurons are nerve cells that are specialized to transmit and receive nervous impulses over long distances. One or more branching dendrites and a single axon help facilitate this transmission by linking neurons to other neurons, sensory cells, and muscle cells. The site where neuron communication occurs, that is where the axon of one cell meets a dendrite, axon, or body of another cell, is called a synapse.

Sagittal Rat Brain Sample Stained for GFAP and NF-P - Traditionally neurons have been thought of as the primary cells of the brain, while glia were considered to play solely a supportive role. In recent years, glia, which are about 10 times more abundant in the human brain than neurons, have come to be understood as more important than previously assumed. Though formerly believed to not have synapses and to be unable to release neurotransmitters, research now suggests that as least some glial cells are synaptically linked with other cells and release neurotransmitters in response to certain stimuli.

Distribution of Neurons and Glia in Neural Tissue - Interest in the brain extends throughout history, though its function has been periodically debated. Archaeological evidence suggests that brain surgery was practiced as early as the Neolithic period, and many texts describing the brain were composed by the ancient Greeks. The Greek physician Hippocrates, who is often referred to as the father of medicine, considered the brain as the seat of the senses and wisdom. Aristotle, however, whose philosophies were extremely influential on Western thought, believed that the soul, intelligence, and motor control sprung from the heart rather than the brain, which he considered to be an organ of minor importance (a similar view was held by the ancient Egyptians).

Employing Immunofluorescence to Label Rat Brain Tissue for Myelin CNPase and Glial Fibrillary Acidic Protein - The outer mantle of the brain, known as the cerebral cortex, is highly folded in humans, though its appearance varies in other animals. In rats, for example, the cerebral cortex is almost entirely smooth, lacking the numerous sulci and gyri typical of the surface of the human brain. Despite this difference, the thickness of the cerebral cortex is nearly the same from species to species. The organization of the cerebral cortex at a cellular level is laminar, with six layers visible in most cortical areas.

Sagittal Rat Brain Section Stained with Alexa Fluor Dyes and a Popular Nuclear Counterstain - Rodents have been successfully bred that have brains that are partially composed of human brain cells. Such animals are usually referred to as chimeras by scientists, a reference to the Greek mythological monster usually depicted as an amalgam of a serpent, lion, and goat. Though chimeras of this type may someday lead to breakthroughs in Parkinson’s disease or Alzheimer’s disease research, they are often at the center of ethical debates.

Glial Fibrillary Acidic Protein and Heavy Chain Neurofilament Subunits in Brain Tissue - A tiny microscope developed by research teams at Bell Labs and the Max-Planck Institute for Medical Research has enabled the imaging of the brain of a live, moving rat. The device only weighs about 25 grams and employs multiphoton fluorescence. Because it is so small, the microscope can be attached to the head of a rat so that images can be obtained through a window in its cranium while it is free to roam about its environment. Fluorescent agents introduced into the bloodstream of the animal facilitate the targeting of specific components of the brain.

Neural Tissue Labeled for GFAP, Myelin BP, and DNA - Myelin is white matter composed of lipids and proteins that sheaths the axons of many nerve cells. The material is formed by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. Axons that are myelinated are able to transmit nervous impulses much faster than unmyelinated axons. Breaks in the myelin sheath termed the nodes of Ranvier have an abundance of sodium channels and facilitate the conduction of impulses in leaps (saltatory movement) rather than waves.

Localizing Fluorescent Tags to Myelinated Nerve Fibers in Brain Tissue Samples - Cerebral palsy, which was first described in 1860 by British surgeon William Little, is a disability linked to brain injury occurring before, during, or soon after birth while the brain is still in a developmental stage. Underlying causes of cerebral palsy are various, cases being linked to an assortment of diseases, physical abuse, smoking, drinking, or drug abuse by the mother during pregnancy, low birth weight, and asphyxia during the birth process. The disability is characterized by loss of voluntary control of the muscles and poor coordination.

Strata of the Rat Brain Visualized with Double Immunofluorescence and Synthetic Fluorophores - Migraines are severe headaches that are often recurrent. Sufferers of migraines commonly experience nausea and photosensitivity in conjunction with throbbing or pounding pain in the head. In some individuals, an aura appears before the onset of the headache. The aura can consist of a variety of neurological symptoms, such as brief loss of vision or seeing flashing lights. The exact cause of migraine headaches is not known for certain, but research suggests that they are frequently related to a change in the blood flow of the brain.

The Blood Brain Barrier Targeted in a Sagittal Tissue Section - When an excess of electrical activity suddenly occurs in the brain a seizure may ensue. Seizures are commonly manifested as spasms, convulsions, or loss of consciousness, but the exact type of a seizure an individual experiences depends on location and pattern of abnormal electrical activity in the brain. Epileptic seizures are usually described as either generalized or partial, the former involving the entire brain and the latter only involving a portion of the organ.

Distribution of Neurofilament Protein and Glial Fibrillary Acidic Protein in Samples of Rat Brain Tissue - A stroke (also known as a cerebrovascular accident) is a sudden loss of brain function that occurs when the supply of blood to the organ is interrupted. Strokes most commonly occur due to blood vessel blockage, but may also be instigated by intracranial hemorrhaging. Signs that an individual is experiencing a stroke are often highly recognizable, commonly including the sudden onset of numbness on one side of the body, aphasia, confusion, dizziness, loss of balance, and vision impairment in one eye.

Targeting Neurofilaments and Astroglia in a Sagittal Brain Section with Immunofluorescence - Neurotransmitters are chemicals in the nervous system that transmit nerve impulses across synapses between nerve cells and other nerve or muscle cells. Neurotransmitters are stored in the axons of neurons, and their release is triggered by electrical impulses. The effect that a neurotransmitter produces does not depend just on the particular chemical in question, but also on the receptor that receives the transmitted signal.

Rat Brain Tissue Immunofluorescently Labeled for Myelin Binding Protein and GFAP - Oxygen and glucose are provided to the brain by the vasculature of the central nervous system, which is also responsible for the removal of metabolic waste products. Blood vessels that enter the skull through foramina extend deep into the tissues of the brain and are also found on the surface of the organ. The two main sets of vessels that service the brain are the internal carotid arteries and the vertebral arteries. The right and left carotid arteries join together at the brains’ base where they form the basilar artery.

Visualizing the Blood Brain Barrier in Rat CNS Tissue - A number of interconnected cavities known as ventricles are located in the brain. A clear, watery substance called cerebrospinal fluid flows through this ventricular system. Primarily secreted by the choroid plexus, cerebrospinal fluid is absorbed into the bloodstream through arachnoid villi if the pressure in the ventricles is greater than venous pressure. The reverse, however, does not occur; blood does not flow into the ventricular system if venous pressure is higher than ventricular pressure.

Brain Sagittal Section Triple Labeled with Alexa Fluor 488, Alexa Fluor 568, and Hoechst 33342 - A variety of neural subsystems in the brain have been identified by researchers, such as those that guide the movements of the eyes or regulate circadian rhythms. The centers that modulate the electrical signals sent through neural subsystems are referred to as nuclei. These centers are chiefly composed of gray matter, the type of nervous tissue rich in cell bodies and lacking many myelinated axons. Most of the axons of neurons that terminate at a particular nucleus utilize the same neurotransmitter.

Neural Tissue Labeled for GFAP, BBB, and DNA - The brain is often considered to be composed of two basic types of material: gray matter and white matter. Gray matter chiefly consists of cell bodies and dendrites, whereas white matter is primarily made up of myelinated axons. Thus, the white matter of the brain can be considered responsible for the transmission of signals, while gray matter mainly functions in the production of those signals.

Localizing Fluorescent Tags to the Blood Brain Barrier and Glial Cells in Rat Brain Tissue Samples - Similar to other parts of the body, the brain is susceptible to tumor growth. More than 200,000 Americans are diagnosed with brain tumors each year. Only about 20 percent of cases, however, involve primary tumors, which initiate from abnormal brain cells. Metastatic tumors that spread to the brain from other regions of the body account for the rest of the diagnoses.

Myelinated Nerve Fibers and Astroglia Visualized in a Sagittal Section of Rat Brain - The symptoms of brain tumors vary and are chiefly dependent on the size and location of the abnormal growth. For example, a tumor located in the occipital lobe might interfere with vision, whereas a tumor in the parietal lobe would be more likely to produce speech abnormalities. More general problems, such as headaches, nausea, vomiting, and seizures may develop most anywhere a tumor develops in the brain if it becomes large enough due to increased cranial pressure.

Targeting Nerve Cell Sheaths with Anti-Myelin CNPase Antibodies - The hippocampal formation is an assembly that is deeply seated within the brain in the temporal lobe. It is composed of three main structures: the hippocampus, the dentate gyrus, and the subiculum. Together these components form part of the limbic system, which plays an important role in emotions and memory formation. The limbic system was one of the first parts of the brain to evolve, and is found in fish, reptiles, and amphibians, as well as mammals.

Immunofluorescently Labeled Myelin and Astroglia in a Sagittal Section of Rat Brain Tissue - The coordination of the voluntary muscles of the body primarily takes place in the cerebellum, a structure located behind the brain stem. The cerebellum communicates with the motor cortex and spinocerebellar cortex via numerous neural pathways, enabling it to transmit signals to the muscles and to receive information about their positioning. The cerebellum contains the majority of neurons in the human brain, but because most of the cells are small granule cells, the structure only comprises about 10 percent of the organ’s total volume.

Glial Fibrillary Acidic Protein and Heavy Chain Neurofilament Subunits in a Horizontal Tissue Section - Invertebrate organisms do not have centralized brains, but rather have nervous systems that feature simple reflex pathways composed of associations of nerve cells. In most invertebrates, these pathways are controlled by localized collections of nerve cell bodies known as ganglia. Over the course of evolutionary history, as nervous systems increased in complexity, groups of ganglia became more and more centralized, eventually leading to the vertebrate brain.

Brain Tissue Sample Probed with Alexa Fluor 488, Alexa Fluor 568, and Hoechst 33342 - The pons is an upper portion of the brain stem that serves as a major nerve tract that connects the two halves of the cerebellum. As such, the structure is critical in the coordination of the movements of the right and left sides of the body. Shaped similar to a horseshoe, the pons is also involved in information integration, respiration, taste, eye and head movement control, and states of arousal. Blood is supplied to the pons by the pontine arteries and the cerebellar arteries.

Distribution of Myelin Basic Protein and GFAP in a Sagittal Section - Located between the brain stem and the cerebral hemispheres is a region of the brain known as the thalamus. The thalamus is a double lobed mass of gray matter that in humans is approximately the size of a small egg. It is separated from the thalamus by a small groove known as the hypothalamic sulcus and forms part of the lateral wall of the third ventricle. In most people, the lobes of the thalamus are connected by the massa intermedia across the ventricle, but in about one-fifth of the population, they are discrete structures.

Localizing Fluorescent Tags to Neurofilaments and Astroglia in Brain Samples - The limbic system is part of the central nervous system that is particularly important for emotional response. Several brain structures comprise the limbic system, including the hippocampus, hypothalamus, amygdala, and other neighboring areas. In addition to emotion, the limbic system is highly involved in the formation of memories. Its effects influence the autonomic nervous system and the endocrine system. The limbic system was one of the first systems of the brain to evolve, and as such, can be found in fish, reptiles, and amphibians, as well as mammalian species.

Neurons, Glial Cells, and DNA Visualized in a Sagittal Rat Brain Tissue Section - The cerebral hemispheres of the human brain, which feature several prominent sulci and gyri, are considered to be divided into several broad regions termed lobes. Four of these lobes, including the parietal, occipital, temporal, and frontal lobes, can be seen along the surface of the brain, while a fifth lobe, known as the insular lobe, is situated in a fissure beneath the others. The lobes do not function independently of one another, but rather are complexly interconnected.

Detecting NF-P and GFAP in Brain Samples with Immunofluorescence - The first known description of the pineal gland was written by Greek physician Galen, who suggested that its name stems from its appearance, which resembles that of a pine nut. Later the seventeenth century mathematician and philosopher René Descartes famously described the pineal gland as the seat of the soul and the site where all thought originates, basing his view in large part on the belief that it was the only part of the brain that was not double. Modern studies suggest that the gland, which is an outgrowth of the posterior wall of the third ventricle, may be an evolutionary predecessor of the eye.

Rat Brain Sagittal Section Stained with a Combination of Alexa Fluor dyes and Hoechst 33342 - Located in the core of the brain stem is a collection of nerve fibers known as the reticular formation. This neural system plays an important role in filtering out familiar or recurring input. Thus, it is critical in regulating states of arousal, awareness, and attention. The reticular formation is also thought to be involved with motor functions and cardiac reflexes. According to some studies, irregularities in this part of the brain may be linked to attention deficit hyperactivity disorder.

Utilizing Antibodies to Target Neurofilaments and Astrocytes - The outer cortex of the mammalian brain is comprised of six strata of neurons, which together are termed the neocortex. These strata usually work interactively, but a few types of brain activity are predominantly associated with a specific layer. The human neocortex is more highly developed than that of any other species and is extensively convoluted. Though it is less than 5 millimeters thick, the surface area of the human neocortex is about 0.5 meters square.

Strata of a Horizontal Rat Brain Section Revealed with Alexa Fluor Conjugates - In the embryo there is a tubular dorsal nerve cord and it is from this cord that the vertebrate central nervous system (including the brain and spinal cord) arises. Early in the differentiation process, the embryonic nerve cord develops three distinct anterior bulges, which are called the forebrain, midbrain, and hindbrain. These same structures comprise the earliest form of the brain thought to have evolved. Later in the progression of both embryonic and evolutionary development, additional divisions of the brain appear.

Brain Tissue Sample Labeled for GFAP, NF-P, and DNA - The portion of the vertebrate brain that is directly continuous with the spinal cord is the medulla oblongata, often simply called the medulla. The medulla is composed of both gray matter and white matter, but unlike most other regions of the brain, the medulla’s white matter is exterior to the gray matter it contains, which surrounds a ventricle. Nerve centers located in the medulla play an important regulatory role in a number of different involuntary nervous activities, such as respiration, digestion, and sleeping.

Distribution of Glia and Neurons in a Horizontal Section of Rat Brain - The multilayered membranes that encapsulate the brain and spinal cord are known as the meninges. The three strata that comprise the meninges include the pia mater, the arachnoid mater, and the dura mater. The pia mater directly lines the brain and spinal cord, both of which are supplied by blood vessels in this innermost membranous layer. A region filled with cerebrospinal fluid, termed the subarachnoid space, is found between the pia mater and arachnoid mater, which is the thin middle meningeal layer.

Immunofluorescently Labeled Neurofilament Protein and Glial Fibrillary Acidic Protein in CNS Tissue - The suprachiasmatic nucleus is a concentrated area of neurons that studies show is fundamental in the maintenance of the daily activity cycles known as circadian rhythms. Located in the hypothalamus, the suprachiasmatic nucleus is a paired structure that essentially functions as a biological clock. In humans, the biological clock is naturally set on an approximately 25 hour cycle, but environmental cues facilitate the maintenance of a 24 hour cycle by most people.

Sagittal Rat Brain Section Stained for Myelin Binding Protein, GFAP, and Nuclear DNA - The midbrain is a part of the brainstem that prominently functions in the integration of sensory input in a number of vertebrates. In mammals, however, this part of the brain does not play a central role in this regard, but rather chiefly serves in the communication of signals to the cerebrum. For example, a pair of specialized centers termed the superior colliculi are well developed in nonmammalian vertebrates and often act as the only site where integration of visual signals occurs. Yet in mammalian species such integration transpires in the cerebral hemispheres and the superior colliculi function primarily in the coordination of visual reflexes.

Employing Double Immunofluorescence to Label Rat Brain Tissue for Neurofilaments and Glial Cells - Studies of rat brain slices suggest that nerve cells comprising cortical systems exhibit spontaneous activity described as neuronal avalanches. The term reflects the fact that the propagation of such activity appears to be governed by the same equations that govern avalanches in nature. This method of signal transmission is thought to be extremely efficient and has been suggested to be particularly important for complex brain functions. Researchers hope that investigations into the nonlinear activity of neurons may help elucidate details of how individual neurons interact to produce network behavior.

Brain Tissue Labeled with Alexa Fluor 488, Alexa Fluor 568, and Hoechst 33342 - Mental illness, a term that encompasses a wide variety of brain disorders, is one of the leading causes of disability in the United States. The basis of many types of mental illness is not known, but a number of disorders are widely considered to have neurochemical origins and are thus often treated with psychiatric medications. Genetics and structural abnormalities of the brain are also sometimes implicated in cases of mental illness, and there has been a long history of controversy about whether or not mental disorders result from nature, nurture, or a combination of both.