Neurobiology

Neurulation

Phase after gastrulation forming the neural tube from mesoderm, ectoderm, and endoderm.

Neural precursor cells

Pluripotent cells giving rise to neurons, controlled by signal molecules and transcription factors.

Neural plate

Earliest nervous system formation at 18 days, triggered by mesoderm and ectoderm contact.

Neural tube

Forms at 22 days from additional folding of the neural plate, crucial for early neuron development.

Prosencephalon

Brain region giving rise to the forebrain, part of the regional brain specification during development.

Retinoic acid (RA)

Inducer of early nervous system development, released from floor and roof plates.

Growth cone

Specialized structure at axon tips guiding axon growth and responding to chemoattraction and chemorepulsion.

Lamellipodium

Large flat extension of axon involved in growth cone structure and axon elongation.

Filopodium

Fine extensions of the lamellipodium, crucial for sensing environmental signals in growth cones.

Cell signaling

Major role in shaping growth cones and axon growth, influenced by diffusible and non-diffusible molecules.

Voltage-gated ion channels

Channels that open or close in response to changes in membrane potential

TRP channels

Ion channels activated by second messengers, like Ca2+, involved in sensory transduction

Chemoattraction

Signals that selectively attract growth cones to specific destinations

Chemorepulsion

Signals that discourage axon growth towards inappropriate targets

Integrin

Non-diffusible factor that mediates cell adhesion to the extracellular matrix

Netrin function

Attractive secreted signals that stimulate growth cone extension via specific receptors

Semaphorin function

Repulsive cues that prevent axon extension by modifying growth cone cytoskeleton

Tropic molecules

Guide axons towards specific sources or destinations

Trophic molecules

Support the survival and growth of neurons and their processes

Topographic map formation

Development of maps based on gradients of molecules that guide axon growth

Integrated networks

Networks of signal molecules and transcription factors controlling neuronal development

Synapse formation initiation

Process involving local recognition between pre- and postsynaptic membranes

Synapse identity development

Differentiation of active zones and postsynaptic density after initial synapse formation

Neurotrophic factors

Factors like NGF and BDNF that regulate neuronal growth, survival, and differentiation

Competition in synapse formation

Process where synapse elimination is modulated by electrical activation and competition

Tyrosine kinase receptors (Trk)

Receptors activated by neurotrophins, regulating cell signaling pathways

Nerve regeneration steps

Process involving degeneration, growth cone formation, and interaction with Schwann cells

Schwann cells in nerve regeneration

Cells that provide molecular support and secrete ECM molecules to facilitate axon regrowth

Motor endplate fate

Fate of the neuromuscular junction after severing the innervating nerve

Role of BDNF and NGF in reinnervation

Enhance tropic and trophic signaling for target recognition and synaptogenesis

Activity in regenerating axons

Activity-dependent mechanisms that influence synapse re-formation during regeneration

Nerve graft

Use of peripheral nerve grafts containing Schwann cells to facilitate nerve regeneration

Glial scarring

Inhibition of CNS regeneration due to the formation of glial scars

Regeneration in the olfactory nerve

Ability of axons to regenerate in the olfactory nerve despite CNS regeneration inhibition

Neurogenesis

The process of generating new nerve cells in the adult vertebrate brain, including humans.

Stem niches

Specialized regions in the adult brain of vertebrates and humans that support the maintenance of stem cells, regulated by neurotrophins and neurotrophin receptors.

Neuroblast migration

Movement of neuroblasts from stem cell niches to their target regions in the brain.

Apoptosis

Programmed cell death mechanism in which cells self-destruct.

Glial scar

Formation of scar tissue in the brain due to the proliferation of glial cells, hindering axon growth.

Excitotoxicity

Mechanism of neuronal cell death caused by elevated neuronal activity due to glutamate release.

NoGo-A

Protein secreted in glial scars that inhibits neurite outgrowth and axon regeneration.

Astrocyte

Glial cell type that produces molecules inhibiting axon growth and promotes glial scarring.

Microglia

Glial cells that clear debris, release inhibitory factors, and hinder axon growth in the CNS.

Olfactory ensheathing cells

Cells that stimulate axon regeneration when injected into the brain, particularly in the olfactory nerve.

Liraglutide Function

Liraglutide is a medication used to treat obesity by reducing appetite and promoting weight loss.

Liraglutide Mechanism

Liraglutide acts by targeting neurons in the hypothalamus to lower appetite.

Hypothalamic Neurons

Liraglutide primarily affects or regulates neurons in the hypothalamus.

Liraglutide and Adipose Tissue

Liraglutide leads to the reduction of adipose tissue and body weight loss through its actions on the hypothalamus.

Neuronal Access

Liraglutide can access neurons in the hypothalamus to exert its effects.

GLP-1 Receptor Role

The GLP-1 Receptor plays a crucial role in regulating food intake and appetite control.