Spine apparatus

[4] The SA is believed to play a role in synaptic plasticity, learning and memory, but the exact function of the spine apparatus is still enigmatic.

The wispy filamentous material is the cytoskeletal network, mainly f-actin, which is responsible for the maintenance and alteration of spine shape.

[5] Consisting of continuous parallel flattened cisternae, the spine apparatus has a large surface area which is important for its function.

The connection to the smooth endoplasmic reticulum suggests a potential pathway for the transfer of proteins and lipids between the spine and dendrite.

[10] The appearance of molecular markers for satellite secretory pathways provides further evidence that the spine apparatus plays a role in local integral membrane protein translocation and processing.

[10] Synaptic activity triggers Ca2+ influx into dendritic spines via NMDA receptors and voltage-dependent calcium channels.

[10] The calcium-sensitive nature of IP3Rs and RyRs makes both receptors capable of regenerative calcium-induced calcium release (CICR).

[15] The spine apparatus’ ability to release calcium into the cytosol is thought to contribute to the development of synaptic plasticity.

Further studies have shown that altered expression and distribution of RyRs, IP3Rs, and L-type voltage-dependent calcium channels (L-VDCCs) can decrease LTP1, LTP2, and LTP3.

Moreover, the spine apparatus is critical for maintaining the cytosolic calcium levels which are central to the formation of synaptic plasticity.