Kisspeptin neurons

From NeuronBankWiki

Kisspeptin fibers make close appositions to GnRH neurons. In this confocal image a single GnRH neuron is shown in green and surrounded by apposed kisspeptin fibers shown in red (Colledge 118).

Kisspeptin is a neuron found in vertebrates. This neuron has been found in animals like rats, horses, mouse, humans and fish, just to name a few.

NS neuron

Kisspeptin is a neuron that directly innervates GnRH neurons and stimulates GnRH release, which activates the reproductive axis. This neuron plays a vital role in pubertal activation and maintenance.

Neuronal Type: Kisspeptin is local interneuron located in the CNS, specifically in the brain.

Anatomy

Location of GnRH neuronal cell bodies in relation to kisspeptin neuronal cell bodies in different species. The number of GnRh cell bodies in the POA and MBH varies between species. (Colledge, 116).

This neuron is located in the hypothalamus. The kisspeptin neuron is present in the Arcuate Nucleus (Arc), Medial Preoptic Area (POA) and Anteroventral periventricular nucleus (AVPV). The frequency of the neuron in each hypothalamic region varies according to the animal.

• Kisspeptin makes close contact with the GnRH neuron, acting as both the cell body and the nerve terminal.
• The distribution of kisspeptin neuronal cell bodies and projections is not well known. In an experiment using adult mice, three areas expressing kisspeptin cell bodies were identified. These areas included the rostral part of the 3rd ventricle, the arcuate nucleus, and very few cells were found in dorsomedial nucleus and posterior hypothalamus.

Physiology

Synaptic Connections

Synaptic Inputs

This neuron recieves most of its input from the AVPV and Arc. Kisspeptins are synthesized from pepetides which are located in the anteroventral periventricular nucleus and arcuate nucleus.

Synaptic Outputs

This neuron output acts locally by activating the GnRH neuron causing the secretion of gonadotropin releasing hormone. GnRH goes via the hypothalamic portal system to the anterior pituitary causing the release of leutinizing hormone and follicle stimulating hormone.

Kisspeptin exerts a potent activational effect on GnRH neurons. Voltage patterns from proestrous female GnRH-GFP neurons in the acute brain slice demonstrate remarkably intense and prolonged activation. (Han, 11352).

Spiking properties

Kisspeptin neurons exhibit spontaneous yet intense spiking pattern.

Behavior

This neuron is typically involved in puberty and reproduction. At the onset of puberty kisspeptin peptide expression begins to occur. This expression activates the hypothalamic-pitutary-gonadol axis. After this process has occured the individual is capable of reproduction.

References

1. Clarkson, J., W. Colledge, A. Caraty, and A. Herbison. "Distribution of Kisspeptin Neurones in the Adult Female Mouse Brain." Journal of Neuroendocrinology 21.8 (2009): 673-82. Print.
2. Colledge, William H. "Kisspeptins and GnRH signaling." Rev. of Kisspeptin reproductive axis. Trends in Endocrinology and Metabolism 25 Dec. 2008: 115-21. PubMed. Web. 27 Aug. 2009. <http://ezproxy.gsu.edu:4366/pubmed/19097915?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum>.
3. Kyu Han, Seong, Michelle Gottsch, Kathy Lee, Simina Popa, Jeremy Smith, and Sonya Jakawich. "Activation of Gonadotropin-Releasing Hormone Neurons." The Journal of Neuroscience 25.49 (2005): 11349-1356. Print.
4. Messager, Sophie, Emmanouella Chatzidaki, Dan Ma, Alan Hendrick, Dirk Zahn, and John Dixon. "Kisspeptin directly stimulates gonadotropin-releasing." Proceedings of the National Academy of Sciences 102.5 (2005): 1761-766. Print.
5. Seminara, Stephanie, Meloni DiPietro, Suresh Ramaswamy, William Crowley, and Tony Plant. "G Protein-Coupled Receptor 54-Induced Gonadotropin-." The Endocrine Society 147.5 (2006): 2122-126. Print.

Additional information

Spiking Pattern