Abstract
Tetramethylrhodamine-dextran is a highly fluorescent neuroanatomical tracer that, in its 10,000 MW form, has seen widespread use as a sensitive anterograde tract-tracing label. We report here the use of a lower molecular weight tetramethylrhodamine-dextran (3000 MW; Molecular Probes, OR) as an in vivo intracellular marker of locomotor-related spinal neurons. In the paralyzed, decerebrate cat preparation, fictive locomotion was evoked by electrical stimulation of the mesencephalic locomotor region. Extracellular and intracellular potentials of rhythmically active spinal neurons were recorded using microelectrodes filled with 2% tetrarnethybrhodamine-dextran (3000 MW) in 0.9% saline (impedance 5-20 Mohm). Following impalement and electrophysiological characterization, neurons were iontophoretically injected for 2-30 min with 3-10 nA of pulsed positive current. Animals were then perfused 30 min to 7 h postinjection with a variety of paraformaldehyde-and glutaraldehyde-containing fixatives. After tissue sectioning, more than 90% of the injected neurons were recovered. Choline acetyltransferase-immunoreactivity could be demonstrated in a subpopulation of tetramethylrhodamine-dextran-labeled neurons. This technique, in addition to producing high-quality electrodes, has the advantages of rapid yet extensive filling of neuronal processes, no tissue processing prior to visualization, and compatibility with immunohistochemistry.
| Original language | English |
|---|---|
| Pages (from-to) | 447-451 |
| Number of pages | 5 |
| Journal | Brain Research Bulletin |
| Volume | 34 |
| Issue number | 5 |
| DOIs | |
| State | Published - Jan 1 1994 |
| Externally published | Yes |
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Keywords
- Dextran amine conjugate
- Fluorescent tracer
- Immunohistochemistry
- Intracellular staining
- Locomotion
- Spinal cord
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Intracellular labeling of cat spinal neurons using a tetramethykhodamine-dextran amine conjugate. / Carr, P. A.; Noga, Brian R; Nance, D. M.; Jordan, L. M.
In: Brain Research Bulletin, Vol. 34, No. 5, 01.01.1994, p. 447-451.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Intracellular labeling of cat spinal neurons using a tetramethykhodamine-dextran amine conjugate
AU - Carr, P. A.
AU - Noga, Brian R
AU - Nance, D. M.
AU - Jordan, L. M.
PY - 1994/1/1
Y1 - 1994/1/1
N2 - Tetramethylrhodamine-dextran is a highly fluorescent neuroanatomical tracer that, in its 10,000 MW form, has seen widespread use as a sensitive anterograde tract-tracing label. We report here the use of a lower molecular weight tetramethylrhodamine-dextran (3000 MW; Molecular Probes, OR) as an in vivo intracellular marker of locomotor-related spinal neurons. In the paralyzed, decerebrate cat preparation, fictive locomotion was evoked by electrical stimulation of the mesencephalic locomotor region. Extracellular and intracellular potentials of rhythmically active spinal neurons were recorded using microelectrodes filled with 2% tetrarnethybrhodamine-dextran (3000 MW) in 0.9% saline (impedance 5-20 Mohm). Following impalement and electrophysiological characterization, neurons were iontophoretically injected for 2-30 min with 3-10 nA of pulsed positive current. Animals were then perfused 30 min to 7 h postinjection with a variety of paraformaldehyde-and glutaraldehyde-containing fixatives. After tissue sectioning, more than 90% of the injected neurons were recovered. Choline acetyltransferase-immunoreactivity could be demonstrated in a subpopulation of tetramethylrhodamine-dextran-labeled neurons. This technique, in addition to producing high-quality electrodes, has the advantages of rapid yet extensive filling of neuronal processes, no tissue processing prior to visualization, and compatibility with immunohistochemistry.
AB - Tetramethylrhodamine-dextran is a highly fluorescent neuroanatomical tracer that, in its 10,000 MW form, has seen widespread use as a sensitive anterograde tract-tracing label. We report here the use of a lower molecular weight tetramethylrhodamine-dextran (3000 MW; Molecular Probes, OR) as an in vivo intracellular marker of locomotor-related spinal neurons. In the paralyzed, decerebrate cat preparation, fictive locomotion was evoked by electrical stimulation of the mesencephalic locomotor region. Extracellular and intracellular potentials of rhythmically active spinal neurons were recorded using microelectrodes filled with 2% tetrarnethybrhodamine-dextran (3000 MW) in 0.9% saline (impedance 5-20 Mohm). Following impalement and electrophysiological characterization, neurons were iontophoretically injected for 2-30 min with 3-10 nA of pulsed positive current. Animals were then perfused 30 min to 7 h postinjection with a variety of paraformaldehyde-and glutaraldehyde-containing fixatives. After tissue sectioning, more than 90% of the injected neurons were recovered. Choline acetyltransferase-immunoreactivity could be demonstrated in a subpopulation of tetramethylrhodamine-dextran-labeled neurons. This technique, in addition to producing high-quality electrodes, has the advantages of rapid yet extensive filling of neuronal processes, no tissue processing prior to visualization, and compatibility with immunohistochemistry.
KW - Dextran amine conjugate
KW - Fluorescent tracer
KW - Immunohistochemistry
KW - Intracellular staining
KW - Locomotion
KW - Spinal cord
UR - http://www.scopus.com/inward/record.url?scp=0028333855&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028333855&partnerID=8YFLogxK
U2 - 10.1016/0361-9230(94)90017-5
DO - 10.1016/0361-9230(94)90017-5
M3 - Article
C2 - 7521780
AN - SCOPUS:0028333855
VL - 34
SP - 447
EP - 451
JO - Brain Research Bulletin
JF - Brain Research Bulletin
SN - 0361-9230
IS - 5
ER -