|
Input Receptors |
Intrinsic Currents |
Output Transmitters |
|
Distal equivalent dendrite
|
|
from mitral cell
|
NMDA
|
| NMDA receptor is required for DDI (dendrodendritic inhibition) since IPSC was completely blocked by AP-5. Ineffectiveness of AMPA receptor-mediated EPSPs to activate the granule cells may be due to their intrinsic membrane properties. (Schoppa NE et al, 19981 ). NMDA receptors play a critical role in dendrodendritic inhibition between mitral and granule cells. Moreover, N- and P/Q type calcium channels are involved. (Isaacson JS and Strowbridge BW, 19982 ). Calcium influx through NMDA receptors can directly trigger presynatic GABA release for local dendrodendritic feedback inhibition. DDI is elicited by photorelease of caged Ca++, with and without Cd++ and Ni++. (Chen WR et al, 20003 ). Calcium influx through NMDA receptors directly evokes GABA release in granule cells. (Halabisky B et al, 20004 ). |
|
mitral (or tufted) cell
|
AMPA
|
| AMPA and NMDA receptors are clustered, and colocalized, on granule cells dendritic spines. (Sassoè-Pognetto M and Ottersen OP, 20005 ). DDI (dendrodendritic inhibition) can be elicited by activation of AMPA receptors, while NMDA receptor activation is not an absolute requirement. DDI is blocked by Cd and toxins to N- and P/Q-type channels. (Isaacson JS, 20016 ). |
|
mitral (or tufted) cell
|
Gaba
|
| There is a selective localization of GABA receptors at symmetric synaptic junctions and of glutamate receptors at asymmetric junctions(Sassoè-Pognetto M and Ottersen OP, 20005 ). |
|
from basal forebrain
|
Cholinergic Receptors
|
| Choline acetyltransferase immunocytochemistry shows that cholinergic projections from the basal forebrain to the main olfactory bulb focus synaptic innervation on interneurons, on the dendritic spines of periglomerular and granule cells. (Kasa P et al, 199510 ). |
|
basal forebrain
|
Muscarinic
|
| Activation of muscarinic receptors decreases granule cell firing frequency, as well as modulates GABAergic synaptic inputs onto mitral cells. (Castillo PE et al, 199911 ). |
|
|
GabaB
|
| It has been suggested in rats that GABA(B) receptors modulate dendrodendritic inhibition primarily by inhibiting granule cell calcium channels and reducing the release of GABA (Isaacson JS and Vitten H, 200313 ). |
|
|
Alpha1
|
| High concentration of NE acts at Alpha1 receptors to increase GC excitability and increase GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
Alpha2
|
| High concentration of NE acts at Alpha2 receptors to decrease GC excitability and decrease GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
mGluR
|
| Activation of mGluR increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
mGluR5
|
| Activation of mGluR5 increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
I p,q
|
| Dendrodendritic inhibition (DDI) between mitral and granule cells relies on N-and P/Q- type calcium channels. Magnitude of DDI is proportional to dendritic calcium influx. (Isaacson JS and Strowbridge BW, 19982 ). |
|
I N
|
| Dendrodendritic inhibition between mitral and granule cells involves N-and P/Q- type calcium channels. The magnitude of DDI is proportional to dendritic calcium influx. (Isaacson JS and Strowbridge BW, 19982 ). |
|
I A
|
| A-channel regulates timing of dendrodendritic inhibition between mitral and granule cells: The transient IA attenuates dendrodendritic input mediated by fast-acting AMPA receptors, such that the excitation and subsequent inhibitory output of granule cells follows the prolonged kinetics of their NMDA receptors. Altering weights of AMPA and NMDA inputs by modulating IA provides a mechanism to regulate the timing of inhibition. A-channels are localized in dendrites. (Schoppa NE and Westbrook GL, 199919 ). |
|
I T low threshold
|
| A study in rat using two-photon microscopy to image calcium transients revealed these channels and suggested a novel mechanism for regulation of lateral inhibition (Egger V et al, 200316 ). Low threshold calcium spikes were antagonized by T-channel blockers in rat (Pinato G and Midtgaard J, 200317 ). |
|
I h
|
| (Holderith NB et al, 2003 [Rat]18 ). histology experiments found Ih in granule cells. |
|
|
Gaba
|
onto mitral cell to exert self inhibition or lateral inhibition
| | GAD-positive gemmules (spines) of granule cells were observed to form reciprocal dendrodentritic synaptic junctions with mitral cell dentrites which lacked reaction product.(Ribak CE et al, 197722 ). GABAergic inhibitory synapses onto mitral cells, through dendrodendritic spine synapse: possibly two types: self inhibition and lateral inhibition. (Rall W and Shepherd GM, 196823 ). (Isaacson JS and Strowbridge BW, 19982 ). Mitral-cell soma-dendrites act as a presynaptic terminal to the granule cell; the circuit is recurrent onto the injected cell; and the inhibitory transmitter is GABA (Jahr CE and Nicoll RA, 198224 ). and Shepherd GM ed. Synaptic Organization of the Brain, 1998. p182)GABA release onto mitral: spontaneous and gltamate-evoked. Moreover, activation of muscarinic receptors modulates GABAergic synaptic inputs onto mitral cell.(Castillo PE et al, 199911 ). Selective localization of GABA receptors at symmetric synapses ( and of gluR at asymmetric synapses.) (Sassoè-Pognetto M and Ottersen OP, 20005 ). |
|
NO
|
mitral cells
| | Nitric oxide, released from both mitral and granule cells, is involved in olfactory memories and may act as a retrograde and/or intracellular messenger. However, only mitral cells expressed guanylyl cyclase subunits. (Kendrick KM et al, 199725 ). |
|
|
Middle equivalent dendrite
|
|
|
GabaB
|
| It has been suggested in rats that GABA(B) receptors modulate dendrodendritic inhibition primarily by inhibiting granule cell calcium channels and reducing the release of GABA (Isaacson JS and Vitten H, 200313 ). |
|
|
Alpha2
|
| High concentration of NE acts at Alpha2 receptors to decrease GC excitability and decrease GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
Alpha1
|
| High concentration of NE acts at Alpha1 receptors to increase GC excitability and increase GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
mGluR5
|
| Activation of mGluR5 increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
mGluR
|
| Activation of mGluR increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
I T low threshold
|
| A study in rat using two-photon microscopy to image calcium transients revealed these channels and suggested a novel mechanism for regulation of lateral inhibition (Egger V et al, 200316 ). Low threshold calcium spikes were antagonized by T-channel blockers in rat (Pinato G and Midtgaard J, 200317 ). |
|
I h
|
| (Holderith NB et al, 2003 [Rat]18 ). histology experiments found Ih in granule cells. |
|
|
|
Proximal equivalent dendrite
|
|
|
GabaB
|
| It has been suggested in rats that GABA(B) receptors modulate dendrodendritic inhibition primarily by inhibiting granule cell calcium channels and reducing the release of GABA (Isaacson JS and Vitten H, 200313 ). |
|
from locus coeruleus
|
Alpha1
|
| High concentration of NE acts at Alpha1 receptors to increase GC excitability and increase GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
Alpha2
|
| High concentration of NE acts at Alpha2 receptors to decrease GC excitability and decrease GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
mGluR5
|
| Activation of mGluR5 increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
mGluR
|
| Activation of mGluR increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
I h
|
| (Holderith NB et al, 2003 [Rat]18 ). histology experiments found Ih in granule cells. |
|
I T low threshold
|
| A study in rat using two-photon microscopy to image calcium transients revealed these channels and suggested a novel mechanism for regulation of lateral inhibition (Egger V et al, 200316 ). Low threshold calcium spikes were antagonized by T-channel blockers in rat (Pinato G and Midtgaard J, 200317 ). |
|
|
|
Soma
|
|
study in primary culture
|
Glycine
|
| Glycine and GABA elicit concentration-dependent desensitizing currents mediated by chloride. (Trombley PQ and Shepherd GM, 19947 ). |
|
primary culture
|
GabaA
|
| Glycine and GABA elicit concentration-dependent desensitizing currents mediated by chloride. (Trombley PQ and Shepherd GM, 19947 ). Cell-specifc modulation of GABAA receptor- mediated chloride current by dopamine. In interneurons (mainly granule cells), dopamine reduces GABAA Cl- current, via D1 receptor and involves phosphorylation of GABAA receptors by PKA. In mitral cell, dopamine enhances GABA responses via activation of D2 receptors and phosphorylation of GABAA receptors via PKC. (Brünig I et al, 19998 ). |
|
primary culture
|
Dopaminergic Receptor
|
| Cell-specifc modulation of GABAA receptor- mediated chloride current by dopamine. In interneurons (mainly granule cells), dopamine reduces GABAA Cl- current, via D1 receptor and involves phosphorylation of GABAA receptors by PKA. In mitral cell, dopamine enhances GABA responses via activation of D2 receptors and phosphorylation of GABAA receptors via PKC. (Brünig I et al, 19998 ). |
|
culture cells
|
Nicotinic
|
| Application of acetylcholine (ACh) evoked concentration-dependent whole-cell currents (Alkondon M et al, 19969 ). |
|
basal forebrain
|
Muscarinic
|
| Activation of muscarinic receptors decreases granule cell firing frequency, as well as modulates GABAergic synaptic inputs onto mitral cells. (Castillo PE et al, 199911 ). |
|
from basal forebrain
|
Cholinergic Receptors
|
| Choline acetyltransferase immunocytochemistry shows that cholinergic projections from the basal forebrain to the main olfactory bulb focus synaptic innervation on interneurons, on the dendritic spines of periglomerular and granule cells. (Kasa P et al, 199510 ). |
|
|
Kainate
|
| In an immunocytochemical study in zebrafish 60-70% of cells showed KA receptor mediated labelling (Edwards JG and Michel WC, 200312 ). |
|
|
NMDA
|
| In an immunocytochemical study in zebrafish all cells resulted in NMDA receptor mediated labelling (Edwards JG and Michel WC, 200312 ). |
|
from Locus coeruleus
|
Alpha1
|
| High concentration of NE acts at Alpha1 receptors to increase GC excitability and increase GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
from locus coeruleus
|
Alpha2
|
| High concentration of NE acts at Alpha2 receptors to decrease GC excitability and decrease GABAergic inhibition inhibition of MC (Nai Q et al, 2010 [Rat]14 ). |
|
|
mGluR5
|
| Activation of mGluR5 increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
mGluR
|
| Activation of mGluR increases GC excitability, an effect that should increase GC-mediated GABAergic inhibition of mitral cells (Heinbockel T et al, 2007 [Rat, Mouse]15 ). |
|
|
I T low threshold
|
| A study in rat using two-photon microscopy to image calcium transients revealed these channels and suggested a novel mechanism for regulation of lateral inhibition (Egger V et al, 200316 ). Low threshold calcium spikes were antagonized by T-channel blockers in rat (Pinato G and Midtgaard J, 200317 ). |
|
I A
|
| mRNA of A-channel subunit Kv4.2 is expressed predominantly in granule cells. (In contrast, that of Kv4.3, also of A-channel, is expressed predominantly in periglomerular cells) (Serôdio P and Rudy B, 199820 ). |
|
I CAN
|
| This current was studied by combining intracellular recordings and two-photon microscopy imaging of [Ca]i (Hall BJ and Delaney KR, 200221 ). |
|
I h
|
| (Holderith NB et al, 2003 [Rat]18 ). histology experiments found Ih in granule cells. |
|
|
Gaba
|
| | GAD-positive staining (Ribak CE et al, 197722 ). |
|
