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Functional imaging of hippocampal place cells at cellular resolution during virtual navigation.

Dombeck DA, Harvey CD, Tian L, Looger LL, Tank DW - Nat. Neurosci. (2010)

Bottom Line: Neurons that expressed the genetically encoded calcium indicator GCaMP3 were imaged through a chronic hippocampal window.Head-restrained mice performed spatial behaviors in a setup combining a virtual reality system and a custom-built two-photon microscope.We optically identified populations of place cells and determined the correlation between the location of their place fields in the virtual environment and their anatomical location in the local circuit.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology and Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey, USA. ddombeck@princeton.edu

ABSTRACT
Spatial navigation is often used as a behavioral task in studies of the neuronal circuits that underlie cognition, learning and memory in rodents. The combination of in vivo microscopy with genetically encoded indicators has provided an important new tool for studying neuronal circuits, but has been technically difficult to apply during navigation. Here we describe methods for imaging the activity of neurons in the CA1 region of the hippocampus with subcellular resolution in behaving mice. Neurons that expressed the genetically encoded calcium indicator GCaMP3 were imaged through a chronic hippocampal window. Head-restrained mice performed spatial behaviors in a setup combining a virtual reality system and a custom-built two-photon microscope. We optically identified populations of place cells and determined the correlation between the location of their place fields in the virtual environment and their anatomical location in the local circuit. The combination of virtual reality and high-resolution functional imaging should allow a new generation of studies to investigate neuronal circuit dynamics during behavior.

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Imaging place related activity in dendrites and putative interneurons. a,b. A two-photon image (b) of a field of view ∼75 microns ventral to the stratum pyramidale cell body layer (dashed line in a). Bright spots in (b) are a cross-section through the apical dendrites from the overlying CA1 neurons. c. Mean ΔF/F versus linear track position for the dendrites labeled in the image in (b). d,e. A two-photon image (e) of a field of view ∼50 microns dorsal to the stratum pyramidale cell body layer (dashed line in d). Sparsely distributed cell bodies in (e) are assumed interneurons. f. Mean ΔF/F versus linear track position for the interneurons labeled in the image in (e).
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Figure 7: Imaging place related activity in dendrites and putative interneurons. a,b. A two-photon image (b) of a field of view ∼75 microns ventral to the stratum pyramidale cell body layer (dashed line in a). Bright spots in (b) are a cross-section through the apical dendrites from the overlying CA1 neurons. c. Mean ΔF/F versus linear track position for the dendrites labeled in the image in (b). d,e. A two-photon image (e) of a field of view ∼50 microns dorsal to the stratum pyramidale cell body layer (dashed line in d). Sparsely distributed cell bodies in (e) are assumed interneurons. f. Mean ΔF/F versus linear track position for the interneurons labeled in the image in (e).

Mentions: To test whether our imaging method had the resolution and signal-to-noise ratio capable of recording activity patterns from dendrites, time-series were acquired ∼75 microns ventral to stratum pyramidale (Fig. 7a, dashed line). In this plane, apical dendrites from the overlying pyramidal neurons could be identified (individual bright spots in Fig. 7b). When the mean activity versus linear track position was plotted, well-defined place fields were found in many of the apical dendrites (Fig. 7c). Dendrites were imaged in 4 fields of view (∼50 dendrites per field) in 3 mice; spatially modulated dendritic activity patterns were seen in all of the fields. Back-propagating action potentials are known to invade the dendritic arbors of CA1 pyramidal neurons32,33. Therefore, it is likely that the activity in the apical dendrites is due to back-propagating action potential-induced opening of voltage gated calcium channels rather than the smaller calcium transients associated with synaptic input.


Functional imaging of hippocampal place cells at cellular resolution during virtual navigation.

Dombeck DA, Harvey CD, Tian L, Looger LL, Tank DW - Nat. Neurosci. (2010)

Imaging place related activity in dendrites and putative interneurons. a,b. A two-photon image (b) of a field of view ∼75 microns ventral to the stratum pyramidale cell body layer (dashed line in a). Bright spots in (b) are a cross-section through the apical dendrites from the overlying CA1 neurons. c. Mean ΔF/F versus linear track position for the dendrites labeled in the image in (b). d,e. A two-photon image (e) of a field of view ∼50 microns dorsal to the stratum pyramidale cell body layer (dashed line in d). Sparsely distributed cell bodies in (e) are assumed interneurons. f. Mean ΔF/F versus linear track position for the interneurons labeled in the image in (e).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2967725&req=5

Figure 7: Imaging place related activity in dendrites and putative interneurons. a,b. A two-photon image (b) of a field of view ∼75 microns ventral to the stratum pyramidale cell body layer (dashed line in a). Bright spots in (b) are a cross-section through the apical dendrites from the overlying CA1 neurons. c. Mean ΔF/F versus linear track position for the dendrites labeled in the image in (b). d,e. A two-photon image (e) of a field of view ∼50 microns dorsal to the stratum pyramidale cell body layer (dashed line in d). Sparsely distributed cell bodies in (e) are assumed interneurons. f. Mean ΔF/F versus linear track position for the interneurons labeled in the image in (e).
Mentions: To test whether our imaging method had the resolution and signal-to-noise ratio capable of recording activity patterns from dendrites, time-series were acquired ∼75 microns ventral to stratum pyramidale (Fig. 7a, dashed line). In this plane, apical dendrites from the overlying pyramidal neurons could be identified (individual bright spots in Fig. 7b). When the mean activity versus linear track position was plotted, well-defined place fields were found in many of the apical dendrites (Fig. 7c). Dendrites were imaged in 4 fields of view (∼50 dendrites per field) in 3 mice; spatially modulated dendritic activity patterns were seen in all of the fields. Back-propagating action potentials are known to invade the dendritic arbors of CA1 pyramidal neurons32,33. Therefore, it is likely that the activity in the apical dendrites is due to back-propagating action potential-induced opening of voltage gated calcium channels rather than the smaller calcium transients associated with synaptic input.

Bottom Line: Neurons that expressed the genetically encoded calcium indicator GCaMP3 were imaged through a chronic hippocampal window.Head-restrained mice performed spatial behaviors in a setup combining a virtual reality system and a custom-built two-photon microscope.We optically identified populations of place cells and determined the correlation between the location of their place fields in the virtual environment and their anatomical location in the local circuit.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology and Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey, USA. ddombeck@princeton.edu

ABSTRACT
Spatial navigation is often used as a behavioral task in studies of the neuronal circuits that underlie cognition, learning and memory in rodents. The combination of in vivo microscopy with genetically encoded indicators has provided an important new tool for studying neuronal circuits, but has been technically difficult to apply during navigation. Here we describe methods for imaging the activity of neurons in the CA1 region of the hippocampus with subcellular resolution in behaving mice. Neurons that expressed the genetically encoded calcium indicator GCaMP3 were imaged through a chronic hippocampal window. Head-restrained mice performed spatial behaviors in a setup combining a virtual reality system and a custom-built two-photon microscope. We optically identified populations of place cells and determined the correlation between the location of their place fields in the virtual environment and their anatomical location in the local circuit. The combination of virtual reality and high-resolution functional imaging should allow a new generation of studies to investigate neuronal circuit dynamics during behavior.

Show MeSH
Related in: MedlinePlus