Differential origin of reticulospinal drive to motoneurons innervating trunk and hindlimb muscles in the mouse revealed by optical recording.
To better understand how the brainstem reticular formation controls and coordinates trunk and hindlimb muscle activity, we used optical recording to characterize the functional connections between medullary reticulospinal neurons and lumbar motoneurons of the L2 segment in the neonatal mouse. In an isolated brainstem-spinal cord preparation, synaptically induced calcium transients were visualized in individual MNs of the ipsilateral and contralateral medial and lateral motor columns (MMC, LMC) following focal electrical stimulation of the medullary reticular formation (MRF). Stimulation of the MRF elicited differential responses in MMC and LMC, according to a specific spatial organization. Stimulation of the medial MRF elicited responses predominantly in the LMC whereas stimulation of the lateral MRF elicited responses predominantly in the MMC. This reciprocal response pattern was observed on both the ipsilateral and contralateral sides of the spinal cord. To ascertain whether the regions stimulated contained reticulospinal neurons, we retrogradely labelled MRF neurons with axons coursing in different spinal funiculi, and compared the distributions of the labelled neurons to the stimulation sites. We found a large number of retrogradely labelled neurons within regions of the gigantocellularis reticular nucleus (including its pars ventralis and alpha) where most stimulation sites were located. The existence of a mediolateral organization within the MRF, whereby distinct populations of reticulospinal neurons predominantly influence medial or lateral motoneurons, provides an anatomical substrate for the differential control of trunk and hindlimb muscles. Such an organization introduces flexibility in the initiation and coordination of activity in the two sets of muscles that would satisfy many of the functional requirements that arise during postural and non-postural motor control in mammals.
Szokol
Karolina
K
University of Oslo, Institute of Basic Medical Sciences (Domus Medica), Department of Physiology, N-0317, Oslo, Norway.
Glover
Joel C
JC
Perreault
Marie-Claude
MC
D000818:Animals; D000831:Animals, Newborn; D004558:Electric Stimulation; D004594:Electrophysiology; D006614:Hindlimb / Q000294:innervation*; D051379:Mice; D008807:Mice, Inbred BALB C; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology*; D011187:Posture / Q000502:physiology; D012154:Reticular Formation / Q000166:cytology / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology* / Q000502:physiology*
Prog Brain Res. 2004;143:231-7
14653168
J Physiol. 2007 Jul 1;582(Pt 1):163-75
17463049
Brain Res. 2006 Apr 21;1084(1):16-27
16616050
J Neurophysiol. 1993 Jun;69(6):2232-47
8350141
J Comp Neurol. 2005 Mar 14;483(3):304-17
15682391
J Neurophysiol. 1986 Feb;55(2):375-401
3950696
Brain Res Dev Brain Res. 1990 Dec 15;57(2):163-74
2073717
Science. 1996 Nov 15;274(5290):1109-15
8895453
Adv Anat Embryol Cell Biol. 1997;135:I-XIV, 1-143
9257458
J Neurophysiol. 1984 May;51(5):968-77
6726321
J Neurophysiol. 2004 Sep;92(3):1958-62
15084639
Brain Res Bull. 1990 Mar;24(3):509-16
2186847
Brain Res. 1979 Jul 6;170(1):23-41
466406
Brain Res Dev Brain Res. 1999 Oct 20;117(1):81-9
10536235
J Physiol Paris. 2006 Nov-Dec;100(5-6):304-16
17658245
J Chem Neuroanat. 2006 Jan;31(1):2-36
16183250
Proc Natl Acad Sci U S A. 2007 Feb 13;104(7):2448-53
17287343
J Neurophysiol. 1995 Sep;74(3):1324-34
7500153
Proc Natl Acad Sci U S A. 2007 Jul 10;104(28):11808-13
17609378
Eur J Neurosci. 2003 Oct;18(8):2273-84
14622188
J Neurosci. 2007 Sep 5;27(36):9670-81
17804628
Neuroscience. 1997 May;78(1):259-70
9135106
J Comp Neurol. 1999 Aug 23;411(2):288-300
10404254
J Neurophysiol. 2004 Oct;92(4):2217-38
15175364
Neuroscience. 1999;90(4):1543-54
10338319
Neurosci Biobehav Rev. 1998 Jul;22(4):547-53
9595568
Mol Cell Neurosci. 2005 Jan;28(1):30-41
15607939
J Neurophysiol. 1993 Dec;70(6):2241-50
8120580
J Neurophysiol. 2002 May;87(5):2480-9
11976385
Brain Res. 1999 Jan 23;816(2):493-9
9878874
Eur J Neurosci. 2000 May;12(5):1624-34
10792440
Exp Brain Res. 1975 Oct 24;23(4):333-51
1183508
Eur J Neurosci. 1995 Jan 1;7(1):143-51
7711930
J Neurobiol. 1991 Jun;22(4):353-76
1890420
Prog Brain Res. 2000;124:3-21
10943113
Brain Res Rev. 2008 Jan;57(1):192-8
17764749
J Comp Neurol. 1980 Nov 1;194(1):37-56
7440799
Neurosci Res. 1993 Feb;16(2):131-41
8387169
J Comp Neurol. 1980 Nov 1;194(1):1-35
7440792
Physiology (Bethesda). 2006 Jun;21:216-25
16714480
Neurosci Biobehav Rev. 1998 Jul;22(4):555-63
9595569
J Neurosci Methods. 1996 Jan;64(1):75-81
8869487
Prog Brain Res. 2004;143:251-61
14653170
J Comp Neurol. 2003 Feb 24;457(1):87-105
12541327
Eur J Neurosci. 1999 Oct;11(10):3481-7
10564356
J Neurophysiol. 1990 Sep;64(3):767-81
2230923
Neuroscience. 2008 Jan 24;151(2):505-17
18065156
Behav Neurosci. 1998 Oct;112(5):1218-28
9829799
J Comp Neurol. 2008 Feb 20;506(6):960-78
18085592
J Physiol. 2008 Feb 15;586(4):1059-75
18096599
J Neurophysiol. 1995 Jan;73(1):399-406
7714582
Brain Res Bull. 1993;30(3-4):281-9
8457877
Methods. 1999 Jun;18(2):215-21
10356353
Exp Neurol. 1987 Sep;97(3):704-24
3622719
Philos Trans R Soc Lond B Biol Sci. 1981 Aug 12;293(1069):477-508
6115428
J Neurosci. 2003 Jan 15;23(2):587-600
12533619
Eur J Neurosci. 2005 Mar;21(5):1432-6
15813953
Anat Embryol (Berl). 1999 Jun;199(6):539-47
10350134
J Neurosci. 1993 Jan;13(1):285-99
8423474
Brain Res Rev. 2008 Jan;57(1):46-55
17884173
Exp Brain Res. 1988;73(1):198-208
3208857
Brain Res Brain Res Rev. 2000 Apr;32(1):86-114
10751659
Am J Physiol. 1984 Mar;246(3 Pt 2):R389-95
6703094
Exp Brain Res. 1979 Jun 1;36(1):1-20
467530
Brain Res Brain Res Rev. 2002 Oct;40(1-3):118-29
12589911
Behav Brain Res. 1996 Oct;80(1-2):211-5
8905145