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Neurons in the barrel cortex turn into processing whisker and odor signals: a cellular mechanism for the storage and retrieval of associative signals.

Wang D, Zhao J, Gao Z, Chen N, Wen B, Lu W, Lei Z, Chen C, Liu Y, Feng J, Wang JH - Front Cell Neurosci (2015)

Bottom Line: How the neurons are recruited as associative memory cells to encode multiple input signals for their associated storage and distinguishable retrieval remains unclear.After associative learning, the neurons and astrocytes in the sensory cortices are able to store the newly learnt signal (cross-modal memory) besides the innate signal (native-modal memory).Such associative memory cells distinguish the differences of these signals by programming different codes and signify the historical associations of these signals by similar codes in information retrievals.

View Article: PubMed Central - PubMed

Affiliation: State Key Lab of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences Beijing, China.

ABSTRACT
Associative learning and memory are essential to logical thinking and cognition. How the neurons are recruited as associative memory cells to encode multiple input signals for their associated storage and distinguishable retrieval remains unclear. We studied this issue in the barrel cortex by in vivo two-photon calcium imaging, electrophysiology, and neural tracing in our mouse model that the simultaneous whisker and olfaction stimulations led to odorant-induced whisker motion. After this cross-modal reflex arose, the barrel and piriform cortices connected. More than 40% of barrel cortical neurons became to encode odor signal alongside whisker signal. Some of these neurons expressed distinct activity patterns in response to acquired odor signal and innate whisker signal, and others encoded similar pattern in response to these signals. In the meantime, certain barrel cortical astrocytes encoded odorant and whisker signals. After associative learning, the neurons and astrocytes in the sensory cortices are able to store the newly learnt signal (cross-modal memory) besides the innate signal (native-modal memory). Such associative memory cells distinguish the differences of these signals by programming different codes and signify the historical associations of these signals by similar codes in information retrievals.

No MeSH data available.


Related in: MedlinePlus

The activity level and cross-correlation of barrel cortical CR neurons in response to OS and WS. (A) Activity levels from CR neurons in response to WS and OS are different (n = 103 neurons). (B) Shows the percentages of CR neurons with equal strength (RWS = ROS, white bar, 69.9%) vs. distinct strength (RWS≠ ROS, gray, 30.1%). (C) Illustrates correlation coefficients for 18.45% CR neurons with RWS > ROS in response to WS (orange bar) and OS (yellow; p = 0.013; paired t-test). (D) Shows correlation coefficients for 11.65% CR neurons with RWS < ROS in response to WS (orange bar) and OS (yellow, p = 0.04; paired t-test). (E) Shows correlation coefficients for 69.9% CR neurons with RWS = ROS in response to WS (orange bar) and OS (yellow, p = 0.005; paired t-test). The recognition of barrel cortical neurons to WS and OS by encoding their different activity synchronies. *p < 0.05; ***p < 0.001.
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Figure 9: The activity level and cross-correlation of barrel cortical CR neurons in response to OS and WS. (A) Activity levels from CR neurons in response to WS and OS are different (n = 103 neurons). (B) Shows the percentages of CR neurons with equal strength (RWS = ROS, white bar, 69.9%) vs. distinct strength (RWS≠ ROS, gray, 30.1%). (C) Illustrates correlation coefficients for 18.45% CR neurons with RWS > ROS in response to WS (orange bar) and OS (yellow; p = 0.013; paired t-test). (D) Shows correlation coefficients for 11.65% CR neurons with RWS < ROS in response to WS (orange bar) and OS (yellow, p = 0.04; paired t-test). (E) Shows correlation coefficients for 69.9% CR neurons with RWS = ROS in response to WS (orange bar) and OS (yellow, p = 0.005; paired t-test). The recognition of barrel cortical neurons to WS and OS by encoding their different activity synchronies. *p < 0.05; ***p < 0.001.

Mentions: In terms of activity levels, Figures 9A,B shows Ca2+ signals from CR neurons in responses to OS and WS. If the difference of their responses to WS vs. OS is above 2.5 times of standard deviation of averaged values (i.e., RWS≠ ROS), we assume that they are able to distinguish odor and whisker signals. 30.1% neurons respond to WS and OS with different strengths (Figure 9B). The recognition of whisker and odor signals may also be fulfilled by setting the activity levels in some CR neurons. Furthermore, the changes of neuronal responses to WS and OS in the cross-correlation and activity level appear parallel. Correlation coefficients for the neurons with RWS > ROS are 0.56 ± 0.043 in response to WS and 0.374 ± 0.022 to OS (Figure 9C; p = 0.013, paired t-test). Correlation coefficients for the neurons with RWS < ROS are 0.44 ± 0.023 in response to WS and 0.59 ± 0.025 to OS (Figure 9D; p = 0.04; paired t-test). Correlation coefficients for the neurons with RWS = ROS are 0.41 ± 0.035 in response to WS and 0.34 ± 0.024 to OS (Figure 9E; p < 0.005; paired t-test). Thus, the CR neurons in the barrel cortex recognize whisker and odor signals by changing their functional connection and activity level.


Neurons in the barrel cortex turn into processing whisker and odor signals: a cellular mechanism for the storage and retrieval of associative signals.

Wang D, Zhao J, Gao Z, Chen N, Wen B, Lu W, Lei Z, Chen C, Liu Y, Feng J, Wang JH - Front Cell Neurosci (2015)

The activity level and cross-correlation of barrel cortical CR neurons in response to OS and WS. (A) Activity levels from CR neurons in response to WS and OS are different (n = 103 neurons). (B) Shows the percentages of CR neurons with equal strength (RWS = ROS, white bar, 69.9%) vs. distinct strength (RWS≠ ROS, gray, 30.1%). (C) Illustrates correlation coefficients for 18.45% CR neurons with RWS > ROS in response to WS (orange bar) and OS (yellow; p = 0.013; paired t-test). (D) Shows correlation coefficients for 11.65% CR neurons with RWS < ROS in response to WS (orange bar) and OS (yellow, p = 0.04; paired t-test). (E) Shows correlation coefficients for 69.9% CR neurons with RWS = ROS in response to WS (orange bar) and OS (yellow, p = 0.005; paired t-test). The recognition of barrel cortical neurons to WS and OS by encoding their different activity synchronies. *p < 0.05; ***p < 0.001.
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Related In: Results  -  Collection

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Figure 9: The activity level and cross-correlation of barrel cortical CR neurons in response to OS and WS. (A) Activity levels from CR neurons in response to WS and OS are different (n = 103 neurons). (B) Shows the percentages of CR neurons with equal strength (RWS = ROS, white bar, 69.9%) vs. distinct strength (RWS≠ ROS, gray, 30.1%). (C) Illustrates correlation coefficients for 18.45% CR neurons with RWS > ROS in response to WS (orange bar) and OS (yellow; p = 0.013; paired t-test). (D) Shows correlation coefficients for 11.65% CR neurons with RWS < ROS in response to WS (orange bar) and OS (yellow, p = 0.04; paired t-test). (E) Shows correlation coefficients for 69.9% CR neurons with RWS = ROS in response to WS (orange bar) and OS (yellow, p = 0.005; paired t-test). The recognition of barrel cortical neurons to WS and OS by encoding their different activity synchronies. *p < 0.05; ***p < 0.001.
Mentions: In terms of activity levels, Figures 9A,B shows Ca2+ signals from CR neurons in responses to OS and WS. If the difference of their responses to WS vs. OS is above 2.5 times of standard deviation of averaged values (i.e., RWS≠ ROS), we assume that they are able to distinguish odor and whisker signals. 30.1% neurons respond to WS and OS with different strengths (Figure 9B). The recognition of whisker and odor signals may also be fulfilled by setting the activity levels in some CR neurons. Furthermore, the changes of neuronal responses to WS and OS in the cross-correlation and activity level appear parallel. Correlation coefficients for the neurons with RWS > ROS are 0.56 ± 0.043 in response to WS and 0.374 ± 0.022 to OS (Figure 9C; p = 0.013, paired t-test). Correlation coefficients for the neurons with RWS < ROS are 0.44 ± 0.023 in response to WS and 0.59 ± 0.025 to OS (Figure 9D; p = 0.04; paired t-test). Correlation coefficients for the neurons with RWS = ROS are 0.41 ± 0.035 in response to WS and 0.34 ± 0.024 to OS (Figure 9E; p < 0.005; paired t-test). Thus, the CR neurons in the barrel cortex recognize whisker and odor signals by changing their functional connection and activity level.

Bottom Line: How the neurons are recruited as associative memory cells to encode multiple input signals for their associated storage and distinguishable retrieval remains unclear.After associative learning, the neurons and astrocytes in the sensory cortices are able to store the newly learnt signal (cross-modal memory) besides the innate signal (native-modal memory).Such associative memory cells distinguish the differences of these signals by programming different codes and signify the historical associations of these signals by similar codes in information retrievals.

View Article: PubMed Central - PubMed

Affiliation: State Key Lab of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences Beijing, China.

ABSTRACT
Associative learning and memory are essential to logical thinking and cognition. How the neurons are recruited as associative memory cells to encode multiple input signals for their associated storage and distinguishable retrieval remains unclear. We studied this issue in the barrel cortex by in vivo two-photon calcium imaging, electrophysiology, and neural tracing in our mouse model that the simultaneous whisker and olfaction stimulations led to odorant-induced whisker motion. After this cross-modal reflex arose, the barrel and piriform cortices connected. More than 40% of barrel cortical neurons became to encode odor signal alongside whisker signal. Some of these neurons expressed distinct activity patterns in response to acquired odor signal and innate whisker signal, and others encoded similar pattern in response to these signals. In the meantime, certain barrel cortical astrocytes encoded odorant and whisker signals. After associative learning, the neurons and astrocytes in the sensory cortices are able to store the newly learnt signal (cross-modal memory) besides the innate signal (native-modal memory). Such associative memory cells distinguish the differences of these signals by programming different codes and signify the historical associations of these signals by similar codes in information retrievals.

No MeSH data available.


Related in: MedlinePlus