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Transplanted Neural Progenitor Cells from Distinct Sources Migrate Differentially in an Organotypic Model of Brain Injury.

Ngalula KP, Cramer N, Schell MJ, Juliano SL - Front Neurol (2015)

Bottom Line: NPCs derived from the GE tended to be immunoreactive for GABAergic markers while those derived from the neocortex were more strongly immunoreactive for other neuronal markers such as MAP2, TUJ1, or Milli-Mark.Cells transplanted in vitro acquired the electrophysiological characteristics of neurons, including action potential generation and reception of spontaneous synaptic activity.This suggests that transplanted cells differentiate into neurons capable of functionally integrating with the host tissue.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Physiology and Genetics, Uniformed Services University of Health Sciences , Bethesda, MD , USA.

ABSTRACT
Brain injury is a major cause of long-term disability. The possibility exists for exogenously derived neural progenitor cells to repair damage resulting from brain injury, although more information is needed to successfully implement this promising therapy. To test the ability of neural progenitor cells (NPCs) obtained from rats to repair damaged neocortex, we transplanted neural progenitor cell suspensions into normal and injured slice cultures of the neocortex acquired from rats on postnatal day 0-3. Donor cells from E16 embryos were obtained from either the neocortex, including the ventricular zone (VZ) for excitatory cells, ganglionic eminence (GE) for inhibitory cells or a mixed population of the two. Cells were injected into the ventricular/subventricular zone (VZ/SVZ) or directly into the wounded region. Transplanted cells migrated throughout the cortical plate with GE and mixed population donor cells predominately targeting the upper cortical layers, while neocortically derived NPCs from the VZ/SVZ migrated less extensively. In the injured neocortex, transplanted cells moved predominantly into the wounded area. NPCs derived from the GE tended to be immunoreactive for GABAergic markers while those derived from the neocortex were more strongly immunoreactive for other neuronal markers such as MAP2, TUJ1, or Milli-Mark. Cells transplanted in vitro acquired the electrophysiological characteristics of neurons, including action potential generation and reception of spontaneous synaptic activity. This suggests that transplanted cells differentiate into neurons capable of functionally integrating with the host tissue. Together, our data suggest that transplantation of neural progenitor cells holds great potential as an emerging therapeutic intervention for restoring function lost to brain damage.

No MeSH data available.


Related in: MedlinePlus

Electrophysiological recordings. (A) is the Current–frequency relationship of a GFP+ transplanted neuron. The recorded cell showed a linear increase in firing frequency as a function of depolarizing current. The inset in the graph shows the response of the cell to a 14pA depolarization. Note the lack of spike frequency adaptation, a characteristic of fast spiking interneurons. (B) Intracortical stimulation evoked postsynaptic currents in the same neuron. The black trace is the average of 10 individual sweeps (each sweep overlaid in gray). The prolonged barrage of PSPs impinging upon the cell suggests that the transplanted neuron had become integrated into the host circuitry. The image of the brain drawing above shows a schematic representation of the position of a stimulating electrode and site of recording of a labeled cell. (C) Percentage of GFP cells that demonstrated spontaneous synaptic inputs (n = 15), and (D) percentage of GFP cells that showed synaptic activity after electrical stimulation (n = 11). (E–G) An Avidin–Rhodamine reaction cell recording, (E) shows GFP, (F) shows the Neurobiotin reaction and (G) merge of the two. Scale bar: 20 μm.
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Figure 7: Electrophysiological recordings. (A) is the Current–frequency relationship of a GFP+ transplanted neuron. The recorded cell showed a linear increase in firing frequency as a function of depolarizing current. The inset in the graph shows the response of the cell to a 14pA depolarization. Note the lack of spike frequency adaptation, a characteristic of fast spiking interneurons. (B) Intracortical stimulation evoked postsynaptic currents in the same neuron. The black trace is the average of 10 individual sweeps (each sweep overlaid in gray). The prolonged barrage of PSPs impinging upon the cell suggests that the transplanted neuron had become integrated into the host circuitry. The image of the brain drawing above shows a schematic representation of the position of a stimulating electrode and site of recording of a labeled cell. (C) Percentage of GFP cells that demonstrated spontaneous synaptic inputs (n = 15), and (D) percentage of GFP cells that showed synaptic activity after electrical stimulation (n = 11). (E–G) An Avidin–Rhodamine reaction cell recording, (E) shows GFP, (F) shows the Neurobiotin reaction and (G) merge of the two. Scale bar: 20 μm.

Mentions: To optimize our electrophysiological analysis, whole cell recordings were taken from GFP positive transplanted as well as concomitant host cells, which were not labeled, after up to 7 days in culture. These experiments revealed that transplanted cells had significantly more depolarized resting potentials than host cells (Table 4, −30 ± 3 mV, n = 11 versus −52 ± 8 mV, n = 4; p = 0.048) with 5 out of 16 transplant and 1 of 5 host cells firing action potentials spontaneously at rest (Figures 7C,D). Transplanted cells tended to have lower cell capacitances (18 ± 3 pF, n = 16 versus 30 ± 6 pF, n = 5; p = 0.11) and resistances (1580 ± 340 MΩ versus 620 ± 70 MΩ; p = 0.18) (Table 4). Most of the transplanted cells acquired electrophysiological characteristics of neurons with properties that reflected their comparatively immature age. Spontaneous synaptic inputs were present in 60% of the transplanted neurons examined (9 of 15) (Figure 7C) and, in 11 cells tested, 10 (91%) showed synaptic activity evoked by electrical stimulation of the cortex outside the transplant location (Figure 7D). Figure 7A shows an example of a cell stimulated by activating a cortical region some distance away; increasing the current also increased the frequency of firing. Figure 7B shows a similar cell demonstrating synaptic inputs after being stimulated from some distance away in the neocortex (e.g., inset in Figure 7A). After recordings, cells were immunoreacted with an avidin conjugate demonstrating their extended processes as seen in Figures 7E–G. These observations suggest that transplanted cells acquire neuronal phenotypes and integrate into the host tissue, highlighting their therapeutic potential.


Transplanted Neural Progenitor Cells from Distinct Sources Migrate Differentially in an Organotypic Model of Brain Injury.

Ngalula KP, Cramer N, Schell MJ, Juliano SL - Front Neurol (2015)

Electrophysiological recordings. (A) is the Current–frequency relationship of a GFP+ transplanted neuron. The recorded cell showed a linear increase in firing frequency as a function of depolarizing current. The inset in the graph shows the response of the cell to a 14pA depolarization. Note the lack of spike frequency adaptation, a characteristic of fast spiking interneurons. (B) Intracortical stimulation evoked postsynaptic currents in the same neuron. The black trace is the average of 10 individual sweeps (each sweep overlaid in gray). The prolonged barrage of PSPs impinging upon the cell suggests that the transplanted neuron had become integrated into the host circuitry. The image of the brain drawing above shows a schematic representation of the position of a stimulating electrode and site of recording of a labeled cell. (C) Percentage of GFP cells that demonstrated spontaneous synaptic inputs (n = 15), and (D) percentage of GFP cells that showed synaptic activity after electrical stimulation (n = 11). (E–G) An Avidin–Rhodamine reaction cell recording, (E) shows GFP, (F) shows the Neurobiotin reaction and (G) merge of the two. Scale bar: 20 μm.
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Related In: Results  -  Collection

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Show All Figures
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Figure 7: Electrophysiological recordings. (A) is the Current–frequency relationship of a GFP+ transplanted neuron. The recorded cell showed a linear increase in firing frequency as a function of depolarizing current. The inset in the graph shows the response of the cell to a 14pA depolarization. Note the lack of spike frequency adaptation, a characteristic of fast spiking interneurons. (B) Intracortical stimulation evoked postsynaptic currents in the same neuron. The black trace is the average of 10 individual sweeps (each sweep overlaid in gray). The prolonged barrage of PSPs impinging upon the cell suggests that the transplanted neuron had become integrated into the host circuitry. The image of the brain drawing above shows a schematic representation of the position of a stimulating electrode and site of recording of a labeled cell. (C) Percentage of GFP cells that demonstrated spontaneous synaptic inputs (n = 15), and (D) percentage of GFP cells that showed synaptic activity after electrical stimulation (n = 11). (E–G) An Avidin–Rhodamine reaction cell recording, (E) shows GFP, (F) shows the Neurobiotin reaction and (G) merge of the two. Scale bar: 20 μm.
Mentions: To optimize our electrophysiological analysis, whole cell recordings were taken from GFP positive transplanted as well as concomitant host cells, which were not labeled, after up to 7 days in culture. These experiments revealed that transplanted cells had significantly more depolarized resting potentials than host cells (Table 4, −30 ± 3 mV, n = 11 versus −52 ± 8 mV, n = 4; p = 0.048) with 5 out of 16 transplant and 1 of 5 host cells firing action potentials spontaneously at rest (Figures 7C,D). Transplanted cells tended to have lower cell capacitances (18 ± 3 pF, n = 16 versus 30 ± 6 pF, n = 5; p = 0.11) and resistances (1580 ± 340 MΩ versus 620 ± 70 MΩ; p = 0.18) (Table 4). Most of the transplanted cells acquired electrophysiological characteristics of neurons with properties that reflected their comparatively immature age. Spontaneous synaptic inputs were present in 60% of the transplanted neurons examined (9 of 15) (Figure 7C) and, in 11 cells tested, 10 (91%) showed synaptic activity evoked by electrical stimulation of the cortex outside the transplant location (Figure 7D). Figure 7A shows an example of a cell stimulated by activating a cortical region some distance away; increasing the current also increased the frequency of firing. Figure 7B shows a similar cell demonstrating synaptic inputs after being stimulated from some distance away in the neocortex (e.g., inset in Figure 7A). After recordings, cells were immunoreacted with an avidin conjugate demonstrating their extended processes as seen in Figures 7E–G. These observations suggest that transplanted cells acquire neuronal phenotypes and integrate into the host tissue, highlighting their therapeutic potential.

Bottom Line: NPCs derived from the GE tended to be immunoreactive for GABAergic markers while those derived from the neocortex were more strongly immunoreactive for other neuronal markers such as MAP2, TUJ1, or Milli-Mark.Cells transplanted in vitro acquired the electrophysiological characteristics of neurons, including action potential generation and reception of spontaneous synaptic activity.This suggests that transplanted cells differentiate into neurons capable of functionally integrating with the host tissue.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Physiology and Genetics, Uniformed Services University of Health Sciences , Bethesda, MD , USA.

ABSTRACT
Brain injury is a major cause of long-term disability. The possibility exists for exogenously derived neural progenitor cells to repair damage resulting from brain injury, although more information is needed to successfully implement this promising therapy. To test the ability of neural progenitor cells (NPCs) obtained from rats to repair damaged neocortex, we transplanted neural progenitor cell suspensions into normal and injured slice cultures of the neocortex acquired from rats on postnatal day 0-3. Donor cells from E16 embryos were obtained from either the neocortex, including the ventricular zone (VZ) for excitatory cells, ganglionic eminence (GE) for inhibitory cells or a mixed population of the two. Cells were injected into the ventricular/subventricular zone (VZ/SVZ) or directly into the wounded region. Transplanted cells migrated throughout the cortical plate with GE and mixed population donor cells predominately targeting the upper cortical layers, while neocortically derived NPCs from the VZ/SVZ migrated less extensively. In the injured neocortex, transplanted cells moved predominantly into the wounded area. NPCs derived from the GE tended to be immunoreactive for GABAergic markers while those derived from the neocortex were more strongly immunoreactive for other neuronal markers such as MAP2, TUJ1, or Milli-Mark. Cells transplanted in vitro acquired the electrophysiological characteristics of neurons, including action potential generation and reception of spontaneous synaptic activity. This suggests that transplanted cells differentiate into neurons capable of functionally integrating with the host tissue. Together, our data suggest that transplantation of neural progenitor cells holds great potential as an emerging therapeutic intervention for restoring function lost to brain damage.

No MeSH data available.


Related in: MedlinePlus