Spinal cord lumbar motor neuron alpha ACh cell

- SPCD - L - VH - PRINC - motor alpha - - ach
Properties are:  Present   Absent 
Input Receptors
Intrinsic Currents
Output Transmitters
Distal equivalent dendrite
Ia afferents release GLU NMDA
Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).
Ia afferents release GLU AMPA
Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).
I Na,t
Patch recordings of back propagating impulses in dendrites. Variable densities of active channels support variable extents of backpropagating impulse in the dendrites (Larkum ME et al, 1996 [rat]17 ). SOBiv p96).
I p,q
I L high threshold
Electrophysiological evidence shows that N-channels and L-channels are present in all dendritic compartments in turtle motoneurons (Hounsgaard J and Kiehn O, 1993 [turtle]21 ). Immunohistochemical evidence shows that CaV1.3 (an L type channel; seeMembrane Properties Resource) is present in soma and all dendritic compartments in turtle motoneurons (Simon M et al, 2003 [turtle]20 ). The presence of L-channels in all dendritic compartments in mouse motoneurons is supported by electrophysiology and immunehistochemistry (Carlin KP et al, 200022 ).
I N
Electrophysiological evidence shows that N-channels and L-channels are present in all dendritic compartments in turtle motoneurons (Hounsgaard J and Kiehn O, 1993 [turtle]21 ).
Middle equivalent dendrite
Ia afferents release GLU AMPA
Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).
Ia afferents release GLU NMDA
Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).
I p,q
I Na,t
Patch recordings of back propagating impulses in dendrites. Variable densities of active channels support variable extents of backpropagating impulse in the dendrites (Larkum ME et al, 1996 [rat]17 ). SOBiv p96).
I L high threshold
Electrophysiological evidence shows that N-channels and L-channels are present in all dendritic compartments in turtle motoneurons (Hounsgaard J and Kiehn O, 1993 [turtle]21 ). Immunohistochemical evidence shows that CaV1.3 (an L type channel; seeMembrane Properties Resource) is present in soma and all dendritic compartments in turtle motoneurons (Simon M et al, 2003 [turtle]20 ). The presence of L-channels in all dendritic compartments in mouse motoneurons is supported by electrophysiology and immunehistochemistry (Carlin KP et al, 200022 ).
I N
Electrophysiological evidence shows that N-channels and L-channels are present in all dendritic compartments in turtle motoneurons (Hounsgaard J and Kiehn O, 1993 [turtle]21 ).
Proximal equivalent dendrite
Ia afferents release GLU NMDA
Glu from Ia axon terminals (reviewed in (Pinco M and Lev-Tov A, 1993 [rat]10 ). Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).
----- Gaba
GABA from some Renshaw interneurons; IPSPs are Cl- mediated, potentially blocked by picrotoxin (Fyffe RE, 1990 [cat]1 ).
Ia afferents release GLU AMPA
Glu from Ia axon terminals (reviewed in Intracellular recordings: CMQX and NBQX applied at the soma completely block short duration (i.e. near soma) single fiber EPSPs (Walmsley B and Bolton PS, 1994 [cat]2 ). see Burke 1998 for references). Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).
Ia interneurons release GLY Glycine
Glycine from some Renshaw interneurons; IPSPs are Cl- mediated, potentially blocked by strychnine (Cullheim S and Kellerth JO, 1981 [cat]13 ). Ia IPSPs are chloride mediated blocked by strychnine. Ia IPSPs are located near the cell soma (Burke RE et al, 1971 [cat]14 ). reviewed in Ia IPSPs are readily affected by soma current or Cl- injection, indicating location at the soma or proximal dendrites (Burke RE et al, 1971 [cat]14 ). SOBiv p94). Glycine ionophoresis mimics Ia IPSPs (reviewed by SOBiv p94). Ia IPSPs are blocked by strychnine, a known blocker of Glycine receptors (SOBiv p94).
I Na,t
Patch recordings of back propagating impulses in dendrites. Variable densities of active channels support variable extents of backpropagating impulse in the dendrites (Larkum ME et al, 1996 [rat]17 ). SOBiv p96).
I p,q
I L high threshold
Electrophysiological evidence shows that N-channels and L-channels are present in all dendritic compartments in turtle motoneurons (Hounsgaard J and Kiehn O, 1993 [turtle]21 ). Immunohistochemical evidence shows that CaV1.3 (an L type channel; seeMembrane Properties Resource) is present in soma and all dendritic compartments in turtle motoneurons (Simon M et al, 2003 [turtle]20 ). The presence of L-channels in all dendritic compartments in mouse motoneurons is supported by electrophysiology and immunehistochemistry (Carlin KP et al, 200022 ).
I N
Electrophysiological evidence shows that N-channels and L-channels are present in all dendritic compartments in turtle motoneurons (Hounsgaard J and Kiehn O, 1993 [turtle]21 ).
Soma
----- Gaba
GABA from some Renshaw interneurons; IPSPs are Cl- mediated, potentially blocked by picrotoxin (Fyffe RE, 1990 [cat]1 ).
----- Glutamate
Glu from Ia axon terminals (reviewed in
Ia afferents release GLU AMPA
Glu from Ia axon terminals (reviewed in Intracellular recordings: CMQX and NBQX applied at the soma completely block short duration (i.e. near soma) single fiber EPSPs (Walmsley B and Bolton PS, 1994 [cat]2 ). see Burke 1998 for references). Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).Motoneurons have a high density of AMPA receptors (Vandenberghe et al, JNS 20: 7158, 2000). There is evidence that "glutamate receptor-mediated Ca2+ influx, intracellular Ca2+ accumulation, and subsequent cell death" may be involved in the mechanism of selective motoneuron degeneration in amyotrophic lateral sclerosis.
Ia afferents release GLU NMDA
Glu from Ia axon terminals (reviewed in (Pinco M and Lev-Tov A, 1993 [rat]10 ). Single-fiber Ia EPSPs have widely varying shapes (KUNO M, 19643 ). (Burke RE, 19674 ). (Jack JJ et al, 19715 ). (Mendell LM and Henneman E, 19716 ). indicating that Ia synapses are distributed widely over soma-dendrites (confirmed by HRP labelling of Ia afferents on labelled motoneurones: reviewed in (Burke RE and Glenn LL, 1996 [cat]7 ). SOBiv p88). Glutamate is released from Ia terminals Ia synapses are immunoreactive for GLU (Maxwell DJ et al, 1990 [cat]8 ). Ia EPSPs are mediated largely by AMPA receptors (muscle afferents: (Jahr CE and Yoshioka K, 1986 [rat]9 ). single fiber EPSPs: (Walmsley B and Bolton PS, 1994 [cat]2 ). by contrast, (Pinco M and Lev-Tov A, 1993 [rat]10 ). found an NMDA component in neonatal rat. Short-term post-tetanic potentiation (PTP) and depression (PTD) occur (CURTIS DR and ECCLES JC, 196011 ). but not LTP or LTD (SOBiv p90).Postnatal development and properties of these receptors were studied with whole-cell and outside-out patch-clamp. The conductance and relative distribution were independent of age from postnatal day 4 to 14. The results also suggested that their properties differ from those in spinal cord interneurons (Palecek JI et al, 1999 [rat]12 ).
Ia interneurons release GLY Glycine
Glycine from some Renshaw interneurons; IPSPs are Cl- mediated, potentially blocked by strychnine (Cullheim S and Kellerth JO, 1981 [cat]13 ). Ia IPSPs are chloride mediated blocked by strychnine. Ia IPSPs are located near the cell soma (Burke RE et al, 1971 [cat]14 ). reviewed in Ia IPSPs are readily affected by soma current or Cl- injection, indicating location at the soma or proximal dendrites (Burke RE et al, 1971 [cat]14 ). SOBiv p94). Glycine ionophoresis mimics Ia IPSPs (reviewed by SOBiv p94). Ia IPSPs are blocked by strychnine, a known blocker of Glycine receptors (SOBiv p94).
I K,Ca
Intracellular recordings: activation by I AHP causes unstable depolarizing plateau potentials; activated and modulated by 5-HT for decending raphe axons (Hounsgaard J and Kiehn O, 1989 [turtle]15 ). Intracellular recordings: afterhyperpolarization potential inverses during repetitive impulse firing, limiting durations and frequency range of impulse firing (Barrett EF and Barret JN, 1976 [frog]16 ). discussed in Burke 1998).
I Na,t
Original intracellular recordings in vivo Variable densities of active channels support variable extents of backpropagating impulse in the dendrites (Larkum ME et al, 1996 [rat]17 ). SOBiv p96).
I L high threshold
Immunohistochemical evidence shows that CaV1.3 (an L type channel; seeMembrane Properties Resource) is present in soma and all dendritic compartments in turtle motoneurons (Simon M et al, 2003 [turtle]20 ).
Axon hillock
I Na,t
This channel is present in high density in all species. Original intracellular recordings suggesting site of impulse initiation is the axon hillock with backspread into the soma dendrites (FUORTES MG et al, 195718 ). see also (Eccles JC, 195719 ). reviewed in Shepherd 1998). Variable densities of active channels support variable extents of backpropagating impulse in the dendrites (Larkum ME et al, 1996 [rat]17 ). SOBiv p96).
I K
Axon fiber
I Na,t
Axon terminal
I N
inferred
Acetylcholine Skeletal muscle
I Calcium
Immunohistochemical evidence shows that CaV1.3 is present in soma and all dendritic compartments in turtle motoneurons(Simon M et al, 2003 [turtle]20 ).
Classical References: first publications on each compartmental property; search PubMed for complete list
1.  Fyffe RE. (1990) Evidence for separate morphological classes of Renshaw cells in the cat's spinal cord. Brain Res 536:301-4.
2.  Walmsley B and Bolton PS. (1994) An in vivo pharmacological study of single group Ia fibre contacts with motoneurones in the cat spinal cord. J Physiol 481 ( Pt 3):731-41.
3.  KUNO M. (1964) QUANTAL COMPONENTS OF EXCITATORY SYNAPTIC POTENTIALS IN SPINAL MOTONEURONES. J Physiol 175:81-99.
4.  Burke RE. (1967) Composite nature of the monosynaptic excitatory postsynaptic potential. J Neurophysiol 30:1114-37 [Journal] .
5.  Jack JJ, Miller S, Porter R and Redman SJ. (1971) The time course of minimal excitory post-synaptic potentials evoked in spinal motoneurones by group Ia afferent fibres. J Physiol 215:353-80.
6.  Mendell LM and Henneman E. (1971) Terminals of single Ia fibers: location, density, and distribution within a pool of 300 homonymous motoneurons. J Neurophysiol 34:171-87 [Journal] .
7.  Burke RE and Glenn LL. (1996) Horseradish peroxidase study of the spatial and electrotonic distribution of group Ia synapses on type-identified ankle extensor motoneurons in the cat. J Comp Neurol 372:465-85 [Journal] .
8.  Maxwell DJ, Christie WM, Short AD and Brown AG. (1990) Direct observations of synapses between GABA-immunoreactive boutons and muscle afferent terminals in lamina VI of the cat's spinal cord. Brain Res 530:215-22.
9.  Jahr CE and Yoshioka K. (1986) Ia afferent excitation of motoneurones in the in vitro new-born rat spinal cord is selectively antagonized by kynurenate. J Physiol 370:515-30.
10.  Pinco M and Lev-Tov A. (1993) Synaptic excitation of alpha-motoneurons by dorsal root afferents in the neonatal rat spinal cord. J Neurophysiol 70:406-17 [Journal] .
11.  CURTIS DR and ECCLES JC. (1960) Synaptic action during and after repetitive stimulation. J Physiol 150:374-98.
12.  Palecek JI, Abdrachmanova G, Vlachová V and Vyklick L. (1999) Properties of NMDA receptors in rat spinal cord motoneurons. Eur J Neurosci 11:827-36.
13.  Cullheim S and Kellerth JO. (1981) Two kinds of recurrent inhibition of cat spinal alpha-motoneurones as differentiated pharmacologically. J Physiol 312:209-24.
14.  Burke RE, Fedina L and Lundberg A. (1971) Spatial synaptic distribution of recurrent and group Ia inhibitory systems in cat spinal motoneurones. J Physiol 214:305-26.
15.  Hounsgaard J and Kiehn O. (1989) Serotonin-induced bistability of turtle motoneurones caused by a nifedipine-sensitive calcium plateau potential. J Physiol 414:265-82.
16.  Barrett EF and Barret JN. (1976) Separation of two voltage-sensitive potassium currents, and demonstration of a tetrodotoxin-resistant calcium current in frog motoneurones. J Physiol 255:737-74.
17.  Larkum ME, Rioult MG and Lüscher HR. (1996) Propagation of action potentials in the dendrites of neurons from rat spinal cord slice cultures. J Neurophysiol 75:154-70 [Journal] .
18.  FUORTES MG, FRANK K and BECKER MC. (1957) Steps in the production of motoneuron spikes. J Gen Physiol 40:735-52.
19.  Eccles JC. (1957) The Physiology Of Nerve Cells.
20.  Simon M, Perrier JF and Hounsgaard J. (2003) Subcellular distribution of L-type Ca2+ channels responsible for plateau potentials in motoneurons from the lumbar spinal cord of the turtle. Eur J Neurosci 18:258-66.
21.  Hounsgaard J and Kiehn O. (1993) Calcium spikes and calcium plateaux evoked by differential polarization in dendrites of turtle motoneurones in vitro. J Physiol 468:245-59.
22.  Carlin KP, Jones KE, Jiang Z, Jordan LM and Brownstone RM. (2000) Dendritic L-type calcium currents in mouse spinal motoneurons: implications for bistability. Eur J Neurosci 12:1635-46.