Science - USA (2022-01-07)

local and transient depolarizations of dendri-
tic segments and their spines (Dendrite+Spines
pattern), likely corresponding to a combina-
tory of synaptic potentials and dendritic spikes
( 41 – 44 ). Importantly, we also found individual
spines activating independently (Spine-only
pattern), even in the absence of dendritic or
somatic activity. These spine-independent
depolarizations likely represent individual
synaptic potentials, owing to their occurrence
during subthreshold synaptic inputs, their spa-
tial restriction, and their sensitivity to synaptic
blockers ( 6 , 7 , 45 , 46 ). These synaptic depola-
rizations of spines can be large in amplitude,
at least of tens of millivolts ( 16 , 32 , 47 – 49 ). The
presence of spine-independent depolarization
during spontaneous and sensory-evoked activ-
ity implies that spines can compartmentalize
voltage in physiological states in vivo. Indeed,
using two-photon optogenetic activation of
individual spines, we demonstrated this di-
rectly while also revealing that dendritic po-
tentials propagated into spines faithfully.
Thus, our data indicate that the spines act
asymmetrically, with no attenuation of den-
dritic potentials or AP but significant attenua-
tion of synaptic potentials ( 13 , 16 ), maintaining
a voltage gradient with the dendrite ( 50 , 51 ).
The mechanisms underlying spine voltage com-
partmentalization could involve geometrical
and structural factors, passive cable properties,

voltage-sensitive ion channels, or synaptic re-

ceptors ( 18 ). Regardless of the mechanism, our

results show that dendritic spines, in addi-

tion to serving as biochemical compartments,

are also elementary electrical compartments

for synapses. The regulation of the voltage

compartmentalization of synaptic inputs by

spines could be important for synaptic func-

tion ( 52 ), synaptic plasticity ( 8 , 53 ), and den-

dritic integration ( 54 ) and be affected in mental

and neurological diseases ( 55 ).

REFERENCESANDNOTES

1. S. Ramon y Cajal,Rev. Trim. Histol. Norm. Patol. 1 ,1– 10
   (1888).


2. E. G. Gray,Nature 183 , 1592–1593 (1959).


3. K. M. Harris, S. B. Kater,Annu. Rev. Neurosci. 17 , 341– 371
   (1994).


4. R. Yuste,Dendritic Spines(MIT Press, 2010).


5. A. Peters, I. R. Kaiserman-Abramof,Am. J. Anat. 127 , 321– 355
   (1970).


6. R. Yuste, W. Denk,Nature 375 , 682–684 (1995).


7. X. Chen, U. Leischner, N. L. Rochefort, I. Nelken, A. Konnerth,
   Nature 475 , 501–505 (2011).


8. J. C. Magee, D. Johnston,Science 275 , 209–213 (1997).


9. S. J. Lee, Y. Escobedo-Lozoya, E. M. Szatmari, R. Yasuda,
   Nature 458 , 299–304 (2009).


10. J. H. Goldberg, G. Tamas, D. Aronov, R. Yuste,Neuron 40 ,
    807 – 821 (2003).


11. G. J. Soler-Llavina, B. L. Sabatini,Nat. Neurosci. 9 , 798– 806
    (2006).


12. W. Rall, inExcitatory Synaptic Mechanisms, Proceedings of the
    Fifth International Meeting of Neurobiologists, P. Andersen,
    J. Jansen, Eds. (Universitets Forlaget, Oslo, 1970), pp. 175–187.


13. J. J. B. Jack, D. Noble, R. W. Tsien,Electric Current Flow in
    Excitable Cells(Oxford Univ. Press, 1975).
    14. C. Koch, T. Poggio,Proc. R. Soc. London Ser. B 218 , 455– 477
    (1983).
    15. C.Koch,A.Zador,T.H.Brown,Science 256 , 973– 974
    (1992).
    16. D. Johnston, S. M.-S. Wu,Foundations of Cellular
    Neurophysiology(MIT Press, 1995).
    17. D. Tsay, R. Yuste,Trends Neurosci. 27 , 77–83 (2004).
    18. R. Yuste,Annu. Rev. Neurosci. 36 , 429–449 (2013).
    19. Y. Bando, C. Grimm, V. H. Cornejo, R. Yuste,BMC Biol. 17 , 71
    (2019).
    20. M. Nuriya, J. Jiang, B. Nemet, K. B. Eisenthal, R. Yuste,Proc.
    Natl. Acad. Sci. U.S.A. 103 , 786–790 (2006).
    21. M. A. Popovic, X. Gao, N. T. Carnevale, D. Zecevic,Cereb.
    Cortex 24 , 385–395 (2014).
    22. T. Kwon, M. Sakamoto, D. S. Peterka, R. Yuste,Cell Rep. 20 ,
    1100 – 1110 (2017).
    23. C. D. Acker, E. Hoyos, L. M. Loew,eNeuro 3 , ENEURO.0050-
    15.2016 (2016).
    24. K. Svoboda, D. W. Tank, W. Denk,Science 272 , 716– 719
    (1996).
    25. B. L. Bloodgood, B. L. Sabatini,Science 310 , 866– 869
    (2005).
    26. R. Araya, K. B. Eisenthal, R. Yuste,Proc. Natl. Acad. Sci. U.S.A.
    103 , 18799–18804 (2006).
    27. R. Araya, J. Jiang, K. B. Eisenthal, R. Yuste,Proc. Natl. Acad.
    Sci. U.S.A. 103 , 17961–17966 (2006).
    28. B. L. Bloodgood, A. J. Giessel, B. L. Sabatini,PLOS Biol. 7 ,
    e1000190 (2009).
    29. M. T. Harnett, J. K. Makara, N. Spruston, W. L. Kath,
    J. C. Magee,Nature 491 , 599–602 (2012).
    30. J. Tønnesen, G. Katona, B. Rózsa, U. V. Nägerl,Nat. Neurosci.
    17 , 678–685 (2014).
    31. R. Araya, T. P. Vogels, R. Yuste,Proc. Natl. Acad. Sci. U.S.A.
    111 , E2895–E2904 (2014).
    32. K. Jayantet al.,Nat. Nanotechnol. 12 , 335–342 (2017).
    33. F. St-Pierreet al.,Nat. Neurosci. 17 , 884–889 (2014).
    34. V. Villetteet al.,Cell 179 , 1590–1608.e23 (2019).
    35. G. G. Grosset al.,Neuron 78 , 971–985 (2013).
    36. C. R. Rose, Y. Kovalchuk, J. Eilers, A. Konnerth,Pflugers Arch.
    439 , 201–207 (1999).

SCIENCEscience.org 7 JANUARY 2022•VOL 375 ISSUE 6576 85

No stim

No stim

0

5

10

15

20

25

****

0

3

6

9

12

15

• Δ

F/F (%)

Spine stim

stim

Spine

Spine

Dendrite

Dendrite Dendrite

0

5

10

15

20

25

Estimated Voltage (mV)

Estimated Voltage (mV)

n.s.

0

3

6

9

12

15

• Δ

F/

F (%)

SponS

enOpto

0.01

0.1

1

10

100

R

/n

R

den

n.s.

10 pA

50 ms

0

100

200

300

400

500

600

Rn

(M

Ω)

CAG postASAPp2a

-5%

ΔF/F

1 s

920 nm postASAP ChrimsonR

1060 nm

Rden

Rn

Vden

Vsp

Rsp

-50

-40

-30

-20

-10

0

Curren

t(p

A)

-10%

ΔF/F

AB

CD

E

F

G

HI

Fig. 4. Two-photon optogenetics and voltage imaging in vivo.(A) Experimen-
tal design. (B) Construct and representative postASAP fluorescence changes
in soma (light green, raw fluorescence; black, 10-Hz low-pass filtered) during
500-ms stimulation trials (red, 100 mW power). (C) Representative soma (top)
and peak fluorescence response (bottom) during stimulation trials (×10, 500 ms,
100 mW). The dotted circle shows the stimulation area (scale bar, 10mm).
(D) Representative in vivo voltage-clamp recordings during optogenetic stimulation
of proximal dendrites (100 mW, 100 ms) are shown on the left. Peak currents are
shown on the right;−22.7 ± 11.3 pA (mean ± SD), 10 trials (n= 7 cells and 4 animals).
(E) Representative peak fluorescence changes during optogenetic activation of
dendritic shafts are shown on the left [stimulation ROIs are indicated by white

dotted circles; 10 trials, 100 ms, 100 mW; color bar same as (C); scale bar, 5mm].

Peak fluorescence changes in stimulated dendritic shaft (dendrite stim), adjacent

dendritic spine (spine), and unstimulated dendritic shaft (dendrite no stim) are

shown on the right (n= 34 dendrites and 9 animals). (F) Same as (E) during

optogenetic activation of spines (n= 35 spines and 12 animals; scale bar, 5mm).

****p< 0.0001. (G) Simplified electrical model. (H) Resistance ratio (RntoRden) of

Spine-only events during spontaneous (Spon,n= 116), sensory stimuli (Sen,

n= 181), and optogenetic spine stimulation (Opto,n= 35). (I) Values of spine

neck resistance for stimulated spines; median = 213.7 megohms (n= 35 spines).

In (D), (H), and (I), boxes and whiskers represent median (line), 25th to

75th percentiles (box), range (whiskers), and mean as a“+”.

RESEARCH | REPORTS