A dye or tracer substance can be ejected by iontophoresis
into the cytoplasm of a cell (intracellular iontophoresis) or into the intercellular
space (extracellular iontophoresis). Intracellular deposition of a dye or
tracer by microiontophoresis is made to mark the cell for subsequent histological
examination. In extracellular studies, iontophoresis is used to mark brain
sites where recordings have been made. Neuronal projections are also studied
by microiontophoretic application of tracers into specific brain areas. In
such experiments, tracer compounds iontophoresed into the intercellular space
are taken up by axonterminals (retrograde tracing) or by dendrites and somata
(anterograde tracing) and are then intracellularly transported across the
whole cell.
A list of popular dye and tracer substances used in neuroscience
research for track-tracing or site marking. Many of these compounds can be
iontophoresed by our precision BAB-350 iontophoresis
pump designed to deliver iontophoretic currents between 1 and 20 µA.
See references for application examples.
| Compound |
Pipette Concentration |
Ejection polarity/current/time |
References |
| Alcian Blue |
3-8% |
(+) 1 µA; 1-2 min |
|
| Cobalt |
1-50 mM |
(+) 50 nA; 1 hour |
|
| Fast Green |
Saturated |
(-) 2-10 µA; 5-10 min |
2, 15, 22, 24, 39, 48 |
| Fluoro-Gold |
1-4 % |
(+) 1-5 µA; 15-30 min |
3-7, 10, 12, 26, 34, 38, 43, 46 |
| Fluoro-Ruby |
10% |
(+) 5 µA |
35, 46 |
| Horseradish peroxidase |
2.5% |
(-) 10 nA; 10-20 sec |
18, 20, 21, 24, 25, 37, 40, 47 |
| Lucifer Yellow (Lithium) |
5% |
(-) 1-2 nA; 5-10 min |
|
| Methyl Blue |
Saturated |
(-) 1-3 µA; 1-3 min |
|
| Neutral Red |
14 mg/l |
(+) 100-150 nA |
|
| Phaseolus Leucoagglutinin |
2.5% |
(+) 2-7 µA; 15 min |
1, 8, 9, 11, 14, 19, 24, 27-31, 33, 41-45 |
| Pontamine Sky Blue |
2% |
(-) 1-20 µA; 3-10 min |
13, 16, 17, 23, 32, 36 |
| Potassium ferrocyanide |
0.5 M |
(-) 3-10 µA; 10-15 min |
|
| Procion Brilliant Red |
4% |
(-) 40 nA; 1 min |
|
| Procion Yellow |
5% |
(-) 10 nA; 5-10 min |
|
| SITS |
4% |
(-) 8 µA |
35 |
| 1 |
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| 2 |
Ashby CR Jr., Edwards E, and Wang
RY (1994) Electrophysiological evidence for a functional interaction
between 5-HT-1A and 5-HT-2A receptors in the rat medial prefrontal cortex:
An iontophoretic study. Synapse (New York) 17(3): p. 173-181. |
| 3 |
Balaban CD and Beryozkin G (1994)
Vestibular nucleus projections to nucleus tractus solitarius and the
dorsal motor nucleus of the vagus nerve: Potential substrates for vestibulo-autonomic
interactions. Experimental Brain Research 98(2): p. 200-212. |
| 4 |
Bell K, Churchill L, and Kalivas PW
(1995) GABAergic projection from the ventral pallidum and globus pallidus
to the subthalamic nucleus. Synapse (New York) 20(1): p. 10-18. |
| 5 |
Brog JS, Salyapongse A, Deutch AY,
and Zahm DS (1993) The patterns of afferent innervation of the core
and shell in the "Accumbens" part of the rat ventral striatum:
Immunohistochemical detection of retrogradely transported fluoro-gold.
Journal of Comparative Neurology 338(2):p. 255-278. |
| 6 |
Chen S and Aston-Jones G (1996) Extensive
projections from the midbrain periaqueductal gray to the caudal ventrolateral
medulla: A retrograde and anterograde tracing study in the rat. Neuroscience
71(2): p. 443-459. |
| 7 |
Chen S and Su HS (1990) Afferent connections
of the thalamic paraventricular and parataenial nuclei in the rat: A
retrograde tracing study with iontophoretic application of Fluoro-Gold.
Brain Research 522(1): p. 1-6. |
| 8 |
Craig AD (1995) Distribution of brainstem
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Journal of Comparative Neurology 361(2): p. 225-248. |
| 9 |
Csillag A, Szekely AD, and Davies
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in the archistriatum of the domestic chick. Journal of Comparative Neurology
348(3): p. 394-402. |
| 10 |
Cullinan WE, Herman JP, and Watson
SJ (1993) Ventral Subicular Interaction with the Hypothalamic Paraventricular
Nucleus Evidence for A Relay in the Bed Nucleus of the Stria Terminalis.
Journal of Comparative Neurology 332(1): p. 1-20. |
| 11 |
Cullinan WE and Zaborszky L (1991)
Organization of ascending hypothalamic projections to the rostral forebrain
with special reference to the innervation of cholinergic projection
neurons. Journal of Comparative Neurology 306(4): p. 631-667. |
| 12 |
Dado RJ, Burstein R, Cliffer KD, and
Giesler GJ Jr. (1990) Evidence that Fluoro-Gold can be transported avidly
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| 13 |
Davies M, Wilkinson LS, and Roberts
MHT (1988) Evidence for depressant 5-HT1-like receptors on rat brainstem
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| 14 |
Deller T, Nitsch R, and Frotscher
M (1995) Phaseolus vulgaris-leucoagglutinin tracing of commissural fibers
to the rat dentate gyrus: Evidence for a previously unknown commissural
projection to the outer molecular layer. Journal of Comparative Neurology
352(1): p.55-68. |
| 15 |
Dougherty PM, Qiao JT, Wiggins RC,
and Dafny N (1990) Microiontophoresis of cocaine, desipramine, sulpiride,
methysergide, and naloxone in habenula and parafasciculus. Experimental
Neurology 108(3): p. 241-246. |
| 16 |
Eaton SA and Salt TE (1996) Role of
N-methyl-D-aspartate and metabotropic glutamate receptors in corticothalamic
excitatory postsynaptic potentials in vivo. Neuroscience 73(1): p. 1-5. |
| 17 |
Feldman PD and Moises HC (1988) Electrophysiological
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| 18 |
Freire M (1990) HRP-filling of neurons
and axonal arbors in fixed brain slabs. Journal of Neuroscience Methods
35(3): p. 267-276. |
| 19 |
Fritschy JM and Grzanna R (1990) Distribution
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vulgaris leucoagglutinin anterograde tracing in combination with dopamine
.beta.-hydroxylase immunofluorescence. Journal of Comparative Neurology
293(4): p. 616-631. |
| 20 |
Gayer NS and Faull RLM (1988) Connections
of the paraflocculus of the cerebellum with the superior colliculus
in the rat brain. Brain Research 449(1-2): p. 253-270. |
| 21 |
Guldin WO, Akbarian S, and Gruesser
OJ (1992) Cortico-Cortical Connections and Cytoarchitectonics of the
Primate Vestibular Cortex A Study in Squirrel Monkeys Saimiri-Sciureus.
Journal of Comparative Neurology 326(3): p. 375-401. |
| 22 |
Henry DJ and White FJ (1995) The persistence
of behavioral sensitization to cocaine parallels enhanced inhibition
of nucleus accumbens neurons. Journal of Neuroscience 15(9): p. 6287-6299. |
| 23 |
Henry JL (1976) Effects of substance
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| 24 |
Jakeman LB and Reier PJ (1991) Axonal
projections between fetal spinal cord transplants and the adult rat
spinal cord: A neuroanatomical tracing study of local interactions.
Journal of Comparative Neurology 307(2): p. 311-334. |
| 25 |
Joosten EAJ and Van Eden CG (1989)
An anterograde tracer study on the development of corticospinal projections
from the medial prefrontal cortex in the rat. Developmental Brain Research
45(2): p. 313-320. |
| 26 |
Kalivas PW, Churchill L, and Klitenick
MA (1993) GABA and enkephalin projection from the nucleus accumbens
and ventral pallidum to the ventral tegmental area. Neuroscience 57(4):
p. 1047-1060. |
| 27 |
Kirchgessner AL and Gershon MD (1989)
Identification of vagal efferent fibers and putative target neurons
in the enteric nervous system of the rat. Journal of Comparative Neurology
285(1): p. 38-53. |
| 28 |
Kuang RZ and Kalil K (1990) Branching
patterns of corticospinal axon arbors in the rodent. Journal of Comparative
Neurology 292(4): p. 585-598. |
| 29 |
Miettinen R and Freund TF (1992) Convergence
and Segregation of Septal and Median Raphe Inputs Onto Different Subsets
of Hippocampal Inhibitory Interneurons. Brain Research 594(2): p. 263-272. |
| 30 |
Mikkelsen JD (1992) The organization
of the crossed geniculogeniculate pathway of the rat: A Phaseolus vulgaris
leucoagglutinin study. Neuroscience 48(4): p. 953-962. |
| 31 |
Mtui EP, Anwar M, Gomez R, Reis DJ,
and Ruggiero DA (1993) Projections from the nucleus tractus solitarii
to the spinal cord. Journal of Comparative Neurology 337(2): p. 231-252. |
| 32 |
Napier TC, et al. (1995) Substance
P in the ventral pallidum: Projection from the ventral striatum, and
electrophysiological and behavioral consequences of pallidal substance
P. Neuroscience 69(1): p. 59-70. |
| 33 |
Nicholas AP and Hancock MB (1991)
Projections from the rostral ventrolateral medulla to brainstem monoamine
neurons in the rat. Neuroscience Letters 122(1): p. 91-95. |
| 34 |
Pieribone VA and Aston-Jones G (1988)
The iontophoretic application of Fluoro-Gold for the study of afferents
to deep brain nuclei. Brain Research 475(2): p. 259-271. |
| 35 |
Qu T, Dong K, Sugioka K, and Yamadori
T (1996) Demonstration of direct input from the retina to the lateral
habenular nucleus in the albino rat. Brain Research 709: p. 251-258. |
| 36 |
Ravel N, Akaoka H, Gervais R, and
Chouvet G (1990) The effect of acetylcholine on rat olfactory bulb unit
activity. Brain Research Bulletin 24(2): p. 151-156. |
| 37 |
Ross LS and Pollak GD (1989) Differential
ascending projections to aural regions in the 60 kHz contour of the
mustache bat's inferior colliculus. Journal of Neuroscience 9(8): p.
2819-2834. |
| 38 |
Schmued LC and Heimer L (1990) Iontophoretic
injection of fluoro-gold and other fluorescent tracers. Journal of Histochemistry
and Cytochemistry 38(5): p. 721-724. |
| 39 |
Sessler FM, Mah EJ, and Grady SM (1993)
Alterations in Noradrenergic Physiological Characteristics with Doca-Hypertension
Interaction Between Norepinephrine and Gaba in Rat Lateral Hypothalamus.
Brain Research 613(2): p. 259-268. |
| 40 |
Shioda S, Nakai Y, Iwase M, and Homma
I (1990) Electron microscopic studies of medullary synaptic inputs to
vasopressin-containing neurons in the hypothalamic paraventricular nucleus.
Journal of Electron Microscopy 39(6): p. 501-507. |
| 41 |
Shu SY and Peterson GM (1988) Anterograde
and retrograde axonal transport of Phaseolus vulgaris leucoagglutinin
(PHA-L) from the globus pallidus to the striatum of the rat. Journal
of Neuroscience Methods 25(2): p. 175-180. |
| 42 |
Slugg RM and Light AR (1994) Spinal
cord and trigeminal projections to the pontine parabrachial region in
the rat as demonstrated with Phaseolus vulgaris leucoagglutinin. Journal
of Comparative Neurology 339(1): p. 49-61. |
| 43 |
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Pieribone VA, Ennis M, and Shipley MT (1991) Subregions of the periaqueductal
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| 44 |
Van Bockstaele EJ, Pieribone VA, and
Aston-Jones G (1989) Diverse afferents converge on the nucleus paragigantocellularis
in the rat ventrolateral medulla: Retrograde and anterograde tracing
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| 45 |
Van der Want JJL, Wiklund L, Guegan
M, Ruigrok T, and Voogd J (1989) Anterograde tracing of the rat olivocerebellar
system with Phaseolus vulgaris leucoagglutinin (PHA-L): Demonstration
of climbing fiber collateral innervation of the cerebellar nuclei. Journal
of Comparative Neurology 288(1) p. 1-18. |
| 46 |
Varoqueaux F and Poulain P (1994)
Lateral septal projections onto tubero-infundibular neurons in the hypothalamus
of the guinea pig. Cell and Tissue Research 278(2): p. 217-225. |
| 47 |
Veenman CL, Reiner A, and Honig MG
(1992) Biotinylated dextran amine as an anterograde tracer for single-
and double-labeling studies. Journal of Neuroscience Methods 41(3):
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| 48 |
White TD, Tan AM, and Finch DM (1991)
Functional connections of the rat medial cortex and basal forebrain:
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