Neocortex Research Paper

In the Summer of 2015 I had the opportunity of accomplishing my own research project. With the help of my graduate student, I led us to better understand the neural pathway

* Interneurons or Pseudopolare (Spelling) cells form all the neural wiring within the CNS. These have two axons (instead of an axon and a dendrite). One axon communicates with the spinal cord; one with either the skin or muscle. These neurons have two processes. (Examples are dorsal root ganglia cells.)

Shortly after an egg is fertilized stem cells begin to form. These cells are programmed to form every organ and tissue in the body as the baby develops.

Upper motor neurons are created in the motor cortex region of the braina nd brainstem. They are developed by fibroblasts that are reprogrammed into pluripotent stem cells. These stemcells undergo neural induction to form the neural progenitors. However the fibroblasts can also be

How are medially-positioned progenitors affected by diffusible signals? The number of neurons belonging to populations found near or at the centre of the dorsoventral axis of the cord is influenced by signal levels, including Shh and BMPs. A moderate concentration of BMP signaling is needed to generate the correct number of medial interneurons. In zebrafish mutants in which a particular BMP protein is functionally reduced, there was a resulting increase in Lim1+ interneurons (medial interneurons) post-mitotically (Nguyen et al., 2000). Interestingly, further BMP reduction decreases medial interneuron counts, illustrating the fine balance of BMP levels that is needed to establish appropriate medial interneuron expression. Perturbing natural

The concept of neurogenesis being confined to the embryonic stage became less obvious with the onset of discovery of neural stem cells maintained in two distinct regions of the mammalian adult brain namely dentate gyrus (DG) of the hippocampus and the sub ventricular zone (SVZ) of the forebrain lateral ventricles14,18,19. What makes these neural stem cells a more credible target for oncogenic transformation? The continual presence of undifferentiated, mitotically active, self renewable stem cells at the apex of the hierarchy bundled in discrete germinal niches in the mammalian brain throughout the lifespan of an organism allows them to accumulate mutations, thus rendering them vulnerable for neoplastic reprogramming. There has been increasing evidence that the genetic and epigenetic mechanisms that initiate and maintain the NSC developmental state are possibly deregulated in GB to emerge as Glioma initiating cells or Brain tumor stem cells20. The discovery of BTSC has high clinical significance in the neuro-oncology field, as evidenced by major diverse roles it plays in various aspects of tumor growth such as tumor initiation, maintenance, progression, angiogenesis and tumor recurrence owing to therapeutic resistance, some of which are described

The goal of this experiment was to examine the relationship of the spatial organization of neurons within the cortex between human and great apes. The researchers measured horizontal spacing distance (HSD) within the two species, as HSD has been related to various features of the cortex. The primary focus of this study was Layer III, which has been implicated in previous studies regarding HSD. The researchers measured HSD and the gray-level ratio (GLR) in Layer III of both human and ape cortices to assess their hypothesis of whether or not the spatial organization of neurons in the frontal pole actually varies between humans and apes. The researchers

Our focus for this week’s lab was the vertebrate nervous system. The nervous system is composed of two divisions called the central nervous system and the peripheral nervous system. Within these two divisions there are three types of neurons that allow us to recognize changes in our environment and help us to respond accordingly. The three neurons that are found are called sensory neurons, interneurons, and motor neurons.

12-2 Sketch and label the structure of a typical neuron, describe the functions of each component, and classify neurons on the basis of their structure and function.

This insular cortex seems to straddle an interesting divide between the brain functions that we traditionally consider animalistic,

The great majority of the cerebral cortex is represented by the neocortex. It is morphologically divided in six layers and holds from 10 to 14 billion neurons of the human brain. These six layers are numbered with Roman numbers from the surfice to the inner part. The molecular layer (layer I) contains very few neurons; layer II is the external granular; layer III the external pyramidal; layer IV the internal granular; layer V the internal pyramidal; and layer VI the multiform, or fusiform layer. Each cortical layer involves different neuronal shapes, sizes and densities as well as different distributions of nerve

The neocortex is the part of the brain that is responsible for advanced functions like language. A variety of different fat molecules are found here. It is known that the neocortex evolved extremely fast during the human–ape split.

Kandel E R, Schwartz J H, & Jessell T M. (2000). “Principles of neural science” New York: McGraw-Hill. 1227-1246

What is known is that the forebrain roof plate starts to develop soon after neurulation, when roof plate cells, which are the first cohort of cell to exit the cell cycle (Kahane and Kalcheim, 1998) begin to form a thin monolayer. This is the time point when the roof plate starts expressing multiple signaling molecules such as members of the Bmp, Wnt and Fgf families exhibiting different gradients along the anterior-posterior axis (Crossley et al., 2001; Furuta et al., 1997; Shimogori et al., 2004). Roof plate development is a complex process and requires the activity of the same set of signaling molecules which later pattern the dorso-medial structures in the forebrain. Evidence gathered primarily from studies in the chick embryo suggest that correct dorsal-ventral patterning of the forebrain is a pre-requisite for subsequent establishment of roof plate identity. In fact the dorsal-ventral identity of the forebrain is acquired as early as the neural fold stage where Wnt signaling first imparts dorsal character to the forebrain cells which otherwise would exhibit ventral characteristics. However, Wnt signaling alone can only impart the initial dorsal forebrain characteristics manifested as the expression of certain markers. Nonetheless, Wnt signaling together with Fgf8 induces the definitive dorsal forebrain characteristics (Gunhaga et

Human embryonic stem cells (ESCs) are pluripotent cells isolated from blastocysts, and are highly useful in studying human development (Itzkovitz-Eldor et al., 2000 p. 88). Although the National Institute of Health states that “it is not known if iPSCs and embryonic stem cells differ in clinically significant ways”, iPSCs are already being used to achieve the same results as ESCs in some applications without the use of embryos, removing the ethical concern associated with ESCs (National Institutes of Health, 2009). ESCs are capable of differentiating into all cell types, and can be used as a source of differentiated cells. In the report by Itskovitz-Eldor et al., they discuss the induced differentiation of ESCs in suspension into embryoid bodies, including the three embryonic germ layers. The authors state that “the ability to induce formation of human embryoid bodies that contain cells of neuronal, hematopoietic and cardiac origins will be useful in studying early human embryonic development” (Itzkovitz-Eldor et al., 2000 p. 88).